\input texinfo.tex @c -*-texinfo-*- @c Id: texinfo.txi,v 1.128 2004/12/29 15:06:41 karl Exp @c Ordinarily, Texinfo files have the extension .texi. But texinfo.texi @c clashes with texinfo.tex on 8.3 filesystems, so we use texinfo.txi. @c Everything between the start/end of header lines will be passed by @c Emacs's {texinfo,makeinfo}-format region commands. See the `start of @c header' node for more info. @c %**start of header @c makeinfo and texinfo.tex ignore all text before @setfilename. @c @c Ordinarily, the setfilename argument ends with .info. But @c texinfo.info-13 is too long for 14-character filesystems. @setfilename texinfo @c Automake automatically updates version.texi to @set VERSION and @c @set UPDATED to appropriate values. @include version.texi @settitle GNU Texinfo @value{VERSION} @c Define a new index for options. @defcodeindex op @c Put everything except function (command, in this case) names in one @c index (arbitrarily chosen to be the concept index). @syncodeindex op cp @syncodeindex vr cp @syncodeindex pg cp @paragraphindent 2 @c finalout @comment %**end of header @copying This manual is for GNU Texinfo (version @value{VERSION}, @value{UPDATED}), a documentation system that can produce both online information and a printed manual from a single source. Copyright (C) 1988, 1990, 1991, 1992, 1993, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc. @quotation Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with the Front-Cover texts being ``A GNU Manual,'' and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled ``GNU Free Documentation License.'' (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development.'' @end quotation @end copying @dircategory Texinfo documentation system @direntry * Texinfo: (texinfo). The GNU documentation format. * install-info: (texinfo)Invoking install-info. Update info/dir entries. * texi2dvi: (texinfo)Format with texi2dvi. Print Texinfo documents. * texi2pdf: (texinfo)PDF Output. PDF output for Texinfo. * texindex: (texinfo)Format with tex/texindex. Sort Texinfo index files. * makeinfo: (texinfo)Invoking makeinfo. Translate Texinfo source. @end direntry @c Before release, run C-u C-c C-u C-a (texinfo-all-menus-update with a @c prefix arg). This updates the node pointers, which texinfmt.el needs. @c Set smallbook if printing in smallbook format so the example of the @c smallbook font is actually written using smallbook; in bigbook, a kludge @c is used for TeX output. Do this through the -t option to texi2dvi, @c so this same source can be used for other paper sizes as well. @c smallbook @c set smallbook @c @@clear smallbook @c If you like blank pages, add through texi2dvi -t. @c setchapternewpage odd @c Currently undocumented command, 5 December 1993: @c nwnode (Same as node, but no warnings; for `makeinfo'.) @shorttitlepage GNU Texinfo @titlepage @title Texinfo @subtitle The GNU Documentation Format @subtitle for Texinfo version @value{VERSION}, @value{UPDATED} @author Robert J. Chassell @author Richard M. Stallman @c Include the Distribution inside the titlepage so @c that headings are turned off. @page @vskip 0pt plus 1filll @insertcopying @sp 1 Published by the Free Software Foundation @* 59 Temple Place Suite 330 @* Boston, MA 02111-1307 @* USA @* ISBN 1-882114-67-1 @c for version 4.0, September 1999. @c ISBN 1-882114-65-5 is for version 3.12, March 1998. @c ISBN 1-882114-64-7 is for edition 2.24 of November 1996. @c ISBN 1-882114-63-9 is for edition 2.20 of 28 February 1995. @sp 1 Cover art by Etienne Suvasa. @end titlepage @summarycontents @contents @ifnottex @node Top @top Texinfo @insertcopying The first part of this master menu lists the major nodes in this Info document, including the @@-command and concept indices. The rest of the menu lists all the lower level nodes in the document. @end ifnottex @menu * Copying Conditions:: Your rights. * Overview:: Texinfo in brief. * Texinfo Mode:: Using the GNU Emacs Texinfo mode. * Beginning a File:: What is at the beginning of a Texinfo file? * Ending a File:: What is at the end of a Texinfo file? * Structuring:: Creating chapters, sections, appendices, etc. * Nodes:: Writing nodes, the basic unit of Texinfo. * Menus:: Writing menus. * Cross References:: Writing cross references. * Marking Text:: Marking words and phrases as code, keyboard input, meta-syntactic variables, and the like. * Quotations and Examples:: Block quotations, examples, etc. * Lists and Tables:: Itemized or numbered lists, and tables. * Special Displays:: Floating figures and footnotes. * Indices:: Creating indices. * Insertions:: Inserting @@-signs, braces, etc. * Breaks:: Forcing or preventing line and page breaks. * Definition Commands:: Describing functions and the like uniformly. * Conditionals:: Specifying text for only some output cases. * Internationalization:: Supporting languages other than English. * Defining New Texinfo Commands:: User-defined macros and aliases. * Hardcopy:: Output for paper, with @TeX{}. * Creating and Installing Info Files:: Details on Info output. * Generating HTML:: Details on HTML output. * Command List:: All the Texinfo @@-commands. * Tips:: Hints on how to write a Texinfo document. * Sample Texinfo Files:: Complete examples, including full texts. * Include Files:: How to incorporate other Texinfo files. * Headings:: How to write page headings and footings. * Catching Mistakes:: How to find formatting mistakes. * Copying This Manual:: The GNU Free Documentation License. * Command and Variable Index:: A menu containing commands and variables. * Concept Index:: A menu covering many topics. @detailmenu --- The Detailed Node Listing --- Overview of Texinfo * Reporting Bugs:: Submitting effective bug reports. * Using Texinfo:: Create printed or online output. * Output Formats:: Overview of the supported output formats. * Info Files:: What is an Info file? * Printed Books:: Characteristics of a printed book or manual. * Formatting Commands:: @@-commands are used for formatting. * Conventions:: General rules for writing a Texinfo file. * Comments:: Writing comments and ignored text in general. * Minimum:: What a Texinfo file must have. * Six Parts:: Usually, a Texinfo file has six parts. * Short Sample:: A short sample Texinfo file. * History:: Acknowledgements, contributors and genesis. Using Texinfo Mode * Texinfo Mode Overview:: How Texinfo mode can help you. * Emacs Editing:: Texinfo mode adds to GNU Emacs' general purpose editing features. * Inserting:: How to insert frequently used @@-commands. * Showing the Structure:: How to show the structure of a file. * Updating Nodes and Menus:: How to update or create new nodes and menus. * Info Formatting:: How to format for Info. * Printing:: How to format and print part or all of a file. * Texinfo Mode Summary:: Summary of all the Texinfo mode commands. Updating Nodes and Menus * Updating Commands:: Five major updating commands. * Updating Requirements:: How to structure a Texinfo file for using the updating command. * Other Updating Commands:: How to indent descriptions, insert missing nodes lines, and update nodes in sequence. Beginning a Texinfo File * Sample Beginning:: A sample beginning for a Texinfo file. * Texinfo File Header:: The first lines. * Document Permissions:: Ensuring your manual is free. * Titlepage & Copyright Page:: Creating the title and copyright pages. * Contents:: How to create a table of contents. * The Top Node:: Creating the `Top' node and master menu. * Global Document Commands:: Affecting formatting throughout. * Software Copying Permissions:: Ensure that you and others continue to have the right to use and share software. Texinfo File Header * First Line:: The first line of a Texinfo file. * Start of Header:: Formatting a region requires this. * setfilename:: Tell Info the name of the Info file. * settitle:: Create a title for the printed work. * End of Header:: Formatting a region requires this. Document Permissions * copying:: Declare the document's copying permissions. * insertcopying:: Where to insert the permissions. Title and Copyright Pages * titlepage:: Create a title for the printed document. * titlefont center sp:: The @code{@@titlefont}, @code{@@center}, and @code{@@sp} commands. * title subtitle author:: The @code{@@title}, @code{@@subtitle}, and @code{@@author} commands. * Copyright:: How to write the copyright notice and include copying permissions. * end titlepage:: Turn on page headings after the title and copyright pages. * headings on off:: An option for turning headings on and off and double or single sided printing. The `Top' Node and Master Menu * Top Node Example:: * Master Menu Parts:: Global Document Commands * documentdescription:: Document summary for the HTML output. * setchapternewpage:: Start chapters on right-hand pages. * paragraphindent:: Specify paragraph indentation. * firstparagraphindent:: Suppress indentation of the first paragraph. * exampleindent:: Specify environment indentation. Ending a Texinfo File * Printing Indices & Menus:: How to print an index in hardcopy and generate index menus in Info. * File End:: How to mark the end of a file. Chapter Structuring * Tree Structuring:: A manual is like an upside down tree @dots{} * Structuring Command Types:: How to divide a manual into parts. * makeinfo top:: The @code{@@top} command, part of the `Top' node. * chapter:: * unnumbered & appendix:: * majorheading & chapheading:: * section:: * unnumberedsec appendixsec heading:: * subsection:: * unnumberedsubsec appendixsubsec subheading:: * subsubsection:: Commands for the lowest level sections. * Raise/lower sections:: How to change commands' hierarchical level. Nodes * Two Paths:: Different commands to structure Info output and printed output. * Node Menu Illustration:: A diagram, and sample nodes and menus. * node:: Creating nodes, in detail. * makeinfo Pointer Creation:: Letting makeinfo determine node pointers. * anchor:: Defining arbitrary cross-reference targets. The @code{@@node} Command * Node Names:: How to choose node and pointer names. * Writing a Node:: How to write an @code{@@node} line. * Node Line Tips:: Keep names short. * Node Line Requirements:: Keep names unique, without @@-commands. * First Node:: How to write a `Top' node. * makeinfo top command:: How to use the @code{@@top} command. Menus * Menu Location:: Menus go at the ends of short nodes. * Writing a Menu:: What is a menu? * Menu Parts:: A menu entry has three parts. * Less Cluttered Menu Entry:: Two part menu entry. * Menu Example:: Two and three part menu entries. * Other Info Files:: How to refer to a different Info file. Cross References * References:: What cross references are for. * Cross Reference Commands:: A summary of the different commands. * Cross Reference Parts:: A cross reference has several parts. * xref:: Begin a reference with `See' @dots{} * Top Node Naming:: How to refer to the beginning of another file. * ref:: A reference for the last part of a sentence. * pxref:: How to write a parenthetical cross reference. * inforef:: How to refer to an Info-only file. * uref:: How to refer to a uniform resource locator. @code{@@xref} * Reference Syntax:: What a reference looks like and requires. * One Argument:: @code{@@xref} with one argument. * Two Arguments:: @code{@@xref} with two arguments. * Three Arguments:: @code{@@xref} with three arguments. * Four and Five Arguments:: @code{@@xref} with four and five arguments. Marking Words and Phrases * Indicating:: How to indicate definitions, files, etc. * Emphasis:: How to emphasize text. Indicating Definitions, Commands, etc. * Useful Highlighting:: Highlighting provides useful information. * code:: Indicating program code. * kbd:: Showing keyboard input. * key:: Specifying keys. * samp:: A literal sequence of characters. * verb:: A verbatim sequence of characters. * var:: Indicating metasyntactic variables. * env:: Indicating environment variables. * file:: Indicating file names. * command:: Indicating command names. * option:: Indicating option names. * dfn:: Specifying definitions. * cite:: Referring to books not in the Info system. * abbr:: Indicating abbreviations. * acronym:: Indicating acronyms. * indicateurl:: Indicating a World Wide Web reference. * email:: Indicating an electronic mail address. Emphasizing Text * emph & strong:: How to emphasize text in Texinfo. * Smallcaps:: How to use the small caps font. * Fonts:: Various font commands for printed output. Quotations and Examples * Block Enclosing Commands:: Different constructs for different purposes. * quotation:: Writing a quotation. * example:: Writing an example in a fixed-width font. * verbatim:: Writing a verbatim example. * verbatiminclude:: Including a file verbatim. * lisp:: Illustrating Lisp code. * small:: Examples in a smaller font. * display:: Writing an example in the current font. * format:: Writing an example without narrowed margins. * exdent:: Undo indentation on a line. * flushleft & flushright:: Pushing text flush left or flush right. * noindent:: Preventing paragraph indentation. * indent:: Forcing paragraph indentation. * cartouche:: Drawing rounded rectangles around examples. Lists and Tables * Introducing Lists:: Texinfo formats lists for you. * itemize:: How to construct a simple list. * enumerate:: How to construct a numbered list. * Two-column Tables:: How to construct a two-column table. * Multi-column Tables:: How to construct generalized tables. Making a Two-column Table * table:: How to construct a two-column table. * ftable vtable:: Automatic indexing for two-column tables. * itemx:: How to put more entries in the first column. @code{@@multitable}: Multi-column Tables * Multitable Column Widths:: Defining multitable column widths. * Multitable Rows:: Defining multitable rows, with examples. Special Displays * Floats:: Figures, tables, and the like. * Images:: Including graphics and images. * Footnotes:: Writing footnotes. Floats * float:: Producing floating material. * caption shortcaption:: Specifying descriptions for floats. * listoffloats:: A table of contents for floats. Inserting Images * Image Syntax:: * Image Scaling:: Footnotes * Footnote Commands:: How to write a footnote in Texinfo. * Footnote Styles:: Controlling how footnotes appear in Info. Indices * Index Entries:: Choose different words for index entries. * Predefined Indices:: Use different indices for different kinds of entries. * Indexing Commands:: How to make an index entry. * Combining Indices:: How to combine indices. * New Indices:: How to define your own indices. Combining Indices * syncodeindex:: How to merge two indices, using @code{@@code} font for the merged-from index. * synindex:: How to merge two indices, using the default font of the merged-to index. Special Insertions * Atsign Braces Comma:: Inserting @@ and @{@} and ,. * Inserting Space:: How to insert the right amount of space within a sentence. * Inserting Accents:: How to insert accents and special characters. * Dots Bullets:: How to insert dots and bullets. * TeX and copyright:: How to insert the @TeX{} logo and the copyright symbol. * euro:: How to insert the Euro currency symbol. * pounds:: How to insert the pounds currency symbol. * minus:: How to insert a minus sign. * math:: How to format a mathematical expression. * Glyphs:: How to indicate results of evaluation, expansion of macros, errors, etc. Inserting @@ and @{@} and @comma{} * Inserting an Atsign:: * Inserting Braces:: * Inserting a Comma:: Inserting Space * Not Ending a Sentence:: Sometimes a . doesn't end a sentence. * Ending a Sentence:: Sometimes it does. * Multiple Spaces:: Inserting multiple spaces. * dmn:: How to format a dimension. Inserting Ellipsis and Bullets * dots:: How to insert dots @dots{} * bullet:: How to insert a bullet. Inserting @TeX{} and Legal Symbols: @copyright{}, @registeredsymbol{} * tex:: The @TeX{} logos. * copyright symbol:: The copyright symbol (c in a circle). * registered symbol:: The registered symbol (R in a circle). Glyphs for Examples * Glyphs Summary:: * result:: How to show the result of expression. * expansion:: How to indicate an expansion. * Print Glyph:: How to indicate printed output. * Error Glyph:: How to indicate an error message. * Equivalence:: How to indicate equivalence. * Point Glyph:: How to indicate the location of point. Glyphs Summary * result:: * expansion:: * Print Glyph:: * Error Glyph:: * Equivalence:: * Point Glyph:: Forcing and Preventing Breaks * Break Commands:: Summary of break-related commands. * Line Breaks:: Forcing line breaks. * - and hyphenation:: Helping @TeX{} with hyphenation points. * w:: Preventing unwanted line breaks in text. * tie:: Inserting an unbreakable but varying space. * sp:: Inserting blank lines. * page:: Forcing the start of a new page. * group:: Preventing unwanted page breaks. * need:: Another way to prevent unwanted page breaks. Definition Commands * Def Cmd Template:: Writing descriptions using definition commands. * Def Cmd Continuation Lines:: Continuing the heading over source lines. * Optional Arguments:: Handling optional and repeated arguments. * deffnx:: Group two or more `first' lines. * Def Cmds in Detail:: Reference for all the definition commands. * Def Cmd Conventions:: Conventions for writing definitions. * Sample Function Definition:: An example. The Definition Commands * Functions Commands:: Commands for functions and similar entities. * Variables Commands:: Commands for variables and similar entities. * Typed Functions:: Commands for functions in typed languages. * Typed Variables:: Commands for variables in typed languages. * Data Types:: The definition command for data types. * Abstract Objects:: Commands for object-oriented programming. Object-Oriented Programming * Variables: Object-Oriented Variables. * Methods: Object-Oriented Methods. Conditionally Visible Text * Conditional Commands:: Text for a given format. * Conditional Not Commands:: Text for any format other than a given one. * Raw Formatter Commands:: Using raw formatter commands. * set clear value:: Variable tests and substitutions. * Conditional Nesting:: Using conditionals inside conditionals. @code{@@set}, @code{@@clear}, and @code{@@value} * set value:: Expand a flag variable to a string. * ifset ifclear:: Format a region if a flag is set. * value Example:: An easy way to update edition information. Internationalization * documentlanguage:: Declaring the current language. * documentencoding:: Declaring the input encoding. Defining New Texinfo Commands * Defining Macros:: Defining and undefining new commands. * Invoking Macros:: Using a macro, once you've defined it. * Macro Details:: Limitations of Texinfo macros. * alias:: Command aliases. * definfoenclose:: Customized highlighting. Formatting and Printing Hardcopy * Use TeX:: Use @TeX{} to format for hardcopy. * Format with tex/texindex:: How to format with explicit shell commands. * Format with texi2dvi:: A simpler way to format. * Print with lpr:: How to print. * Within Emacs:: How to format and print from an Emacs shell. * Texinfo Mode Printing:: How to format and print in Texinfo mode. * Compile-Command:: How to print using Emacs's compile command. * Requirements Summary:: @TeX{} formatting requirements summary. * Preparing for TeX:: What to do before you use @TeX{}. * Overfull hboxes:: What are and what to do with overfull hboxes. * smallbook:: How to print small format books and manuals. * A4 Paper:: How to print on A4 or A5 paper. * pagesizes:: How to print with customized page sizes. * Cropmarks and Magnification:: How to print marks to indicate the size of pages and how to print scaled up output. * PDF Output:: Portable Document Format output. * Obtaining TeX:: How to Obtain @TeX{}. Creating and Installing Info Files * Creating an Info File:: * Installing an Info File:: Creating an Info File * makeinfo advantages:: @code{makeinfo} provides better error checking. * Invoking makeinfo:: How to run @code{makeinfo} from a shell. * makeinfo options:: Specify fill-column and other options. * Pointer Validation:: How to check that pointers point somewhere. * makeinfo in Emacs:: How to run @code{makeinfo} from Emacs. * texinfo-format commands:: Two Info formatting commands written in Emacs Lisp are an alternative to @code{makeinfo}. * Batch Formatting:: How to format for Info in Emacs Batch mode. * Tag and Split Files:: How tagged and split files help Info to run better. Installing an Info File * Directory File:: The top level menu for all Info files. * New Info File:: Listing a new Info file. * Other Info Directories:: How to specify Info files that are located in other directories. * Installing Dir Entries:: How to specify what menu entry to add to the Info directory. * Invoking install-info:: @code{install-info} options. Generating HTML * HTML Translation:: Details of the HTML output. * HTML Splitting:: How HTML output is split. * HTML CSS:: Influencing HTML output with Cascading Style Sheets. * HTML Xref:: Cross-references in HTML output. HTML Cross-references * Link Basics: HTML Xref Link Basics. * Node Expansion: HTML Xref Node Name Expansion. * Command Expansion: HTML Xref Command Expansion. * 8-bit Expansion: HTML Xref 8-bit Character Expansion. * Mismatch: HTML Xref Mismatch. @@-Command List * Command Syntax:: General syntax for varieties of @@-commands. Sample Texinfo Files * Short Sample Texinfo File:: * GNU Sample Texts:: * Verbatim Copying License:: * All-permissive Copying License:: Copying This Manual * GNU Free Documentation License:: License for copying this manual. Include Files * Using Include Files:: How to use the @code{@@include} command. * texinfo-multiple-files-update:: How to create and update nodes and menus when using included files. * Include Files Requirements:: @code{texinfo-multiple-files-update} needs. * Sample Include File:: A sample outer file with included files within it; and a sample included file. * Include Files Evolution:: How use of the @code{@@include} command has changed over time. Page Headings * Headings Introduced:: Conventions for using page headings. * Heading Format:: Standard page heading formats. * Heading Choice:: How to specify the type of page heading. * Custom Headings:: How to create your own headings and footings. Formatting Mistakes * makeinfo Preferred:: @code{makeinfo} finds errors. * Debugging with Info:: How to catch errors with Info formatting. * Debugging with TeX:: How to catch errors with @TeX{} formatting. * Using texinfo-show-structure:: How to use @code{texinfo-show-structure}. * Using occur:: How to list all lines containing a pattern. * Running Info-Validate:: How to find badly referenced nodes. Finding Badly Referenced Nodes * Using Info-validate:: How to run @code{Info-validate}. * Unsplit:: How to create an unsplit file. * Tagifying:: How to tagify a file. * Splitting:: How to split a file manually. Copying This Manual * GNU Free Documentation License:: License for copying this manual. @end detailmenu @end menu @c Reward readers for getting to the end of the menu :). @c Contributed by Arnold Robbins. @quotation Documentation is like sex: when it is good, it is very, very good; and when it is bad, it is better than nothing. ---Dick Brandon @end quotation @node Copying Conditions @unnumbered Texinfo Copying Conditions @cindex Copying conditions @cindex Conditions for copying Texinfo The programs currently being distributed that relate to Texinfo include @code{makeinfo}, @code{info}, @code{texindex}, and @file{texinfo.tex}. These programs are @dfn{free}; this means that everyone is free to use them and free to redistribute them on a free basis. The Texinfo-related programs are not in the public domain; they are copyrighted and there are restrictions on their distribution, but these restrictions are designed to permit everything that a good cooperating citizen would want to do. What is not allowed is to try to prevent others from further sharing any version of these programs that they might get from you. Specifically, we want to make sure that you have the right to give away copies of the programs that relate to Texinfo, that you receive source code or else can get it if you want it, that you can change these programs or use pieces of them in new free programs, and that you know you can do these things. To make sure that everyone has such rights, we have to forbid you to deprive anyone else of these rights. For example, if you distribute copies of the Texinfo related programs, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must tell them their rights. Also, for our own protection, we must make certain that everyone finds out that there is no warranty for the programs that relate to Texinfo. If these programs are modified by someone else and passed on, we want their recipients to know that what they have is not what we distributed, so that any problems introduced by others will not reflect on our reputation. The precise conditions of the licenses for the programs currently being distributed that relate to Texinfo are found in the General Public Licenses that accompany them. This manual specifically is covered by the GNU Free Documentation License (@pxref{GNU Free Documentation License}). @node Overview @chapter Overview of Texinfo @cindex Overview of Texinfo @cindex Texinfo overview @dfn{Texinfo}@footnote{The first syllable of ``Texinfo'' is pronounced like ``speck'', not ``hex''. This odd pronunciation is derived from, but is not the same as, the pronunciation of @TeX{}. In the word @TeX{}, the @samp{X} is actually the Greek letter ``chi'' rather than the English letter ``ex''. Pronounce @TeX{} as if the @samp{X} were the last sound in the name `Bach'; but pronounce Texinfo as if the @samp{x} were a `k'. Spell ``Texinfo'' with a capital ``T'' and the other letters in lower case.} is a documentation system that uses a single source file to produce both online information and printed output. This means that instead of writing two different documents, one for the online information and the other for a printed work, you need write only one document. Therefore, when the work is revised, you need revise only that one document. @menu * Reporting Bugs:: Submitting effective bug reports. * Using Texinfo:: Create printed or online output. * Output Formats:: Overview of the supported output formats. * Info Files:: What is an Info file? * Printed Books:: Characteristics of a printed book or manual. * Formatting Commands:: @@-commands are used for formatting. * Conventions:: General rules for writing a Texinfo file. * Comments:: Writing comments and ignored text in general. * Minimum:: What a Texinfo file must have. * Six Parts:: Usually, a Texinfo file has six parts. * Short Sample:: A short sample Texinfo file. * History:: Acknowledgements, contributors and genesis. @end menu @node Reporting Bugs @section Reporting Bugs @cindex Bugs, reporting @cindex Suggestions for Texinfo, making @cindex Reporting bugs We welcome bug reports and suggestions for any aspect of the Texinfo system, programs, documentation, installation, anything. Please email them to @email{bug-texinfo@@gnu.org}. You can get the latest version of Texinfo from @uref{ftp://ftp.gnu.org/gnu/texinfo/} and its mirrors worldwide. @cindex Checklist for bug reports For bug reports, please include enough information for the maintainers to reproduce the problem. Generally speaking, that means: @itemize @bullet @item the version number of Texinfo and the program(s) or manual(s) involved. @item hardware and operating system names and versions. @item the contents of any input files necessary to reproduce the bug. @item a description of the problem and samples of any erroneous output. @item any unusual options you gave to @command{configure}. @item anything else that you think would be helpful. @end itemize When in doubt whether something is needed or not, include it. It's better to include too much than to leave out something important. @cindex Patches, contributing Patches are most welcome; if possible, please make them with @samp{@w{diff -c}} (@pxref{Top,, Overview, diff, Comparing and Merging Files}) and include @file{ChangeLog} entries (@pxref{Change Log,,, emacs, The GNU Emacs Manual}). When sending patches, if possible please do not encode or split them in any way; it's much easier to deal with one plain text message, however large, than many small ones. @uref{ftp://ftp.gnu.org/gnu/sharutils/, GNU shar} is a convenient way of packaging multiple and/or binary files for email. @node Using Texinfo @section Using Texinfo @cindex Using Texinfo in general @cindex Texinfo, introduction to @cindex Introduction to Texinfo Using Texinfo, you can create a printed document (via the @TeX{} typesetting system) the normal features of a book, including chapters, sections, cross references, and indices. From the same Texinfo source file, you can create an Info file with special features to make documentation browsing easy. You can also create from that same source file an HTML output file suitable for use with a web browser, or an XML file. See the next section (@pxref{Output Formats}) for details and the exact commands to generate output from the source. @TeX{} works with virtually all printers; Info works with virtually all computer terminals; the HTML output works with virtually all web browsers. Thus Texinfo can be used by almost any computer user. @cindex Source file format A Texinfo source file is a plain @sc{ascii} file containing text interspersed with @dfn{@@-commands} (words preceded by an @samp{@@}) that tell the typesetting and formatting programs what to do. You can edit a Texinfo file with any text editor, but it is especially convenient to use GNU Emacs since that editor has a special mode, called Texinfo mode, that provides various Texinfo-related features. (@xref{Texinfo Mode}.) You can use Texinfo to create both online help and printed manuals; moreover, Texinfo is freely redistributable. For these reasons, Texinfo is the official documentation format of the GNU project. More information is available at the @uref{http://www.gnu.org/doc/, GNU documentation web page}. @node Output Formats @section Output Formats @cindex Output formats @cindex Back-end output formats Here is a brief overview of the output formats currently supported by Texinfo. @table @asis @item Info @cindex Info output (Generated via @command{makeinfo}.) This format is essentially a plain text transliteration of the Texinfo source. It adds a few control characters to separate nodes and provide navigational information for menus, cross-references, indices, and so on. See the next section (@pxref{Info Files}) for more details on this format. The Emacs Info subsystem (@pxref{Top,,Getting Started,info, Info}), and the standalone @command{info} program (@pxref{Top ,, Info Standalone, info-stnd, GNU Info}), among others, can read these files. @xref{Creating and Installing Info Files}. @item Plain text @cindex Plain text output (Generated via @command{makeinfo --no-headers}.) This is almost the same as Info output, except the navigational control characters are omitted. Also, standard output is used by default. @item HTML @cindex HTML output @cindex W3 consortium @cindex Mozilla @cindex Lynx @cindex Emacs-W3 (Generated via @command{makeinfo --html}.) This is the Hyper Text Markup Language that has become the most commonly used language for writing documents on the World Wide Web. Web browsers, such as Mozilla, Lynx, and Emacs-W3, can render this language online. There are many versions of HTML; @command{makeinfo} tries to use a subset of the language that can be interpreted by any common browser. For details of the HTML language and much related information, see @uref{http://www.w3.org/MarkUp/}. @xref{Generating HTML}. @item DVI @cindex DVI output @pindex dvips @pindex xdvi (Generated via @command{texi2dvi}.) This DeVice Independent binary format is output by the @TeX{} typesetting program (@uref{http://tug.org}). This is then read by a DVI `driver', which writes the actual device-specific commands that can be viewed or printed, notably Dvips for translation to PostScript (@pxref{Invoking Dvips,,, dvips, Dvips}) and Xdvi for viewing on an X display (@uref{http://sourceforge.net/projects/xdvi/}). @xref{Hardcopy}. Be aware that the Texinfo language is very different from and much stricter than @TeX{}'s usual languages, plain @TeX{} and @LaTeX{}. For more information on @TeX{} in general, please see the book @cite{@TeX{} for the Impatient}, available from @uref{http://savannah.gnu.org/projects/teximpatient}. @item PDF @cindex PDF output @cindex Beebe, Nelson @pindex pdftex (Generated via @command{texi2dvi --pdf} or @command{texi2pdf}.) This was developed by Adobe Systems for portable document interchange, based on their previous PostScript language. It can represent the exact appearance of a document, including fonts, and supporting arbitrary scaling. It is intended to be platform-independent and easily viewable, among other design goals; for a discussion, see @uref{http://tug.org/TUGboat/Articles/tb22-3/tb72beebeI.pdf}. Texinfo uses the @command{pdftex} program, a variant of @TeX{}, to output PDF; see @uref{http://tug.org/applications/pdftex}. @xref{PDF Output}. @item XML @cindex XML output @cindex DTD, for Texinfo XML @pindex texinfo.dtd (Generated via @command{makeinfo --xml}.) XML is a generic syntax specification usable for any sort of content (see, for example, @uref{http://www.w3.org/XML/}). The @command{makeinfo} xml output, unlike all the formats above, interprets very little of the Texinfo source. Rather, it merely translates the Texinfo markup commands into XML syntax, for processing by further XML tools. The particular syntax output is defined in the file @file{texinfo.dtd} included in the Texinfo source distribution. @item Docbook @cindex Docbook output (Generated via @command{makeinfo --docbook}.) This is an XML-based format developed some years ago, primarily for technical documentation. It therefore bears some resemblance, in broad outlines, to Texinfo. See @uref{http://www.docbook.org}. If you want to convert from Docbook @emph{to} Texinfo, please see @uref{http://docbook2X.sourceforge.net}. @end table @cindex Man page output, not supported From time to time, proposals are made to generate traditional Unix man pages from Texinfo source. However, because man pages have a very strict conventional format, generating a good man page requires a completely different source than the typical Texinfo applications of writing a good user tutorial and/or a good reference manual. This makes generating man pages incompatible with the Texinfo design goal of not having to document the same information in different ways for different output formats. You might as well just write the man page directly. @pindex help2man @cindex O'Dea, Brendan Man pages still have their place, and if you wish to support them, you may find the program @command{help2man} to be useful; it generates a traditional man page from the @samp{--help} output of a program. In fact, this is currently used to generate man pages for the programs in the Texinfo distribution. It is GNU software written by Brendan O'Dea, available from @uref{ftp://ftp.gnu.org/gnu/help2man/}. @cindex Output formats, supporting more @cindex SGML-tools output format If you are a programmer and would like to contribute to the GNU project by implementing additional output formats for Texinfo, that would be excellent. But please do not write a separate translator texi2foo for your favorite format foo! That is the hard way to do the job, and makes extra work in subsequent maintenance, since the Texinfo language is continually being enhanced and updated. Instead, the best approach is modify @code{makeinfo} to generate the new format. @node Info Files @section Info Files @cindex Info files An Info file is a Texinfo file formatted so that the Info documentation reading program can operate on it. (@code{makeinfo} and @code{texinfo-format-buffer} are two commands that convert a Texinfo file into an Info file.) Info files are divided into pieces called @dfn{nodes}, each of which contains the discussion of one topic. Each node has a name, and contains both text for the user to read and pointers to other nodes, which are identified by their names. The Info program displays one node at a time, and provides commands with which the user can move to other related nodes. @xref{Top,,, info, GNU Info}, for more information about using Info. Each node of an Info file may have any number of child nodes that describe subtopics of the node's topic. The names of child nodes are listed in a @dfn{menu} within the parent node; this allows you to use certain Info commands to move to one of the child nodes. Generally, an Info file is organized like a book. If a node is at the logical level of a chapter, its child nodes are at the level of sections; likewise, the child nodes of sections are at the level of subsections. All the children of any one parent are linked together in a bidirectional chain of `Next' and `Previous' pointers. The `Next' pointer provides a link to the next section, and the `Previous' pointer provides a link to the previous section. This means that all the nodes that are at the level of sections within a chapter are linked together. Normally the order in this chain is the same as the order of the children in the parent's menu. Each child node records the parent node name as its `Up' pointer. The last child has no `Next' pointer, and the first child has the parent both as its `Previous' and as its `Up' pointer.@footnote{In some documents, the first child has no `Previous' pointer. Occasionally, the last child has the node name of the next following higher level node as its `Next' pointer.} The book-like structuring of an Info file into nodes that correspond to chapters, sections, and the like is a matter of convention, not a requirement. The `Up', `Previous', and `Next' pointers of a node can point to any other nodes, and a menu can contain any other nodes. Thus, the node structure can be any directed graph. But it is usually more comprehensible to follow a structure that corresponds to the structure of chapters and sections in a printed book or report.@refill In addition to menus and to `Next', `Previous', and `Up' pointers, Info provides pointers of another kind, called references, that can be sprinkled throughout the text. This is usually the best way to represent links that do not fit a hierarchical structure.@refill Usually, you will design a document so that its nodes match the structure of chapters and sections in the printed output. But occasionally there are times when this is not right for the material being discussed. Therefore, Texinfo uses separate commands to specify the node structure for the Info file and the section structure for the printed output.@refill Generally, you enter an Info file through a node that by convention is named `Top'. This node normally contains just a brief summary of the file's purpose, and a large menu through which the rest of the file is reached. From this node, you can either traverse the file systematically by going from node to node, or you can go to a specific node listed in the main menu, or you can search the index menus and then go directly to the node that has the information you want. Alternatively, with the standalone Info program, you can specify specific menu items on the command line (@pxref{Top,,, info, Info}). If you want to read through an Info file in sequence, as if it were a printed manual, you can hit @key{SPC} repeatedly, or you get the whole file with the advanced Info command @kbd{g *}. (@inforef{Advanced, Advanced Info commands, info}.)@refill @c !!! dir file may be located in one of many places: @c /usr/local/emacs/info mentioned in info.c DEFAULT_INFOPATH @c /usr/local/lib/emacs/info mentioned in info.c DEFAULT_INFOPATH @c /usr/gnu/info mentioned in info.c DEFAULT_INFOPATH @c /usr/local/info @c /usr/local/lib/info The @file{dir} file in the @file{info} directory serves as the departure point for the whole Info system. From it, you can reach the `Top' nodes of each of the documents in a complete Info system.@refill @cindex URI syntax for Info If you wish to refer to an Info file in a URI, you can use the (unofficial) syntax exemplified in the following. This works with Emacs/W3, for example: @example info:///usr/info/emacs#Dissociated%20Press info:emacs#Dissociated%20Press info://localhost/usr/info/emacs#Dissociated%20Press @end example The @command{info} program itself does not follow URI's of any kind. @node Printed Books @section Printed Books @cindex Printed book and manual characteristics @cindex Manual characteristics, printed @cindex Book characteristics, printed @cindex Texinfo printed book characteristics @cindex Characteristics, printed books or manuals @cindex Knuth, Donald A Texinfo file can be formatted and typeset as a printed book or manual. To do this, you need @TeX{}, a powerful, sophisticated typesetting program written by Donald Knuth.@footnote{You can also use the @pindex texi2roff@r{, unsupported software} @uref{ftp://tug.org/texi2roff.tar.gz, @code{texi2roff}} program if you do not have @TeX{}; since Texinfo is designed for use with @TeX{}, @code{texi2roff} is not described here. @code{texi2roff} is not part of the standard GNU distribution and is not maintained or up-to-date with all the Texinfo features described in this manual.} A Texinfo-based book is similar to any other typeset, printed work: it can have a title page, copyright page, table of contents, and preface, as well as chapters, numbered or unnumbered sections and subsections, page headers, cross references, footnotes, and indices.@refill You can use Texinfo to write a book without ever having the intention of converting it into online information. You can use Texinfo for writing a printed novel, and even to write a printed memo, although this latter application is not recommended since electronic mail is so much easier.@refill @TeX{} is a general purpose typesetting program. Texinfo provides a file @file{texinfo.tex} that contains information (definitions or @dfn{macros}) that @TeX{} uses when it typesets a Texinfo file. (@file{texinfo.tex} tells @TeX{} how to convert the Texinfo @@-commands to @TeX{} commands, which @TeX{} can then process to create the typeset document.) @file{texinfo.tex} contains the specifications for printing a document. You can get the latest version of @file{texinfo.tex} from @uref{ftp://ftp.gnu.org/gnu/texinfo/texinfo.tex}. In the United States, documents are most often printed on 8.5 inch by 11 inch pages (216@dmn{mm} by 280@dmn{mm}); this is the default size. But you can also print for 7 inch by 9.25 inch pages (178@dmn{mm} by 235@dmn{mm}, the @code{@@smallbook} size; or on A4 or A5 size paper (@code{@@afourpaper}, @code{@@afivepaper}). (@xref{smallbook, , Printing ``Small'' Books}. Also, see @ref{A4 Paper, ,Printing on A4 Paper}.) By changing the parameters in @file{texinfo.tex}, you can change the size of the printed document. In addition, you can change the style in which the printed document is formatted; for example, you can change the sizes and fonts used, the amount of indentation for each paragraph, the degree to which words are hyphenated, and the like. By changing the specifications, you can make a book look dignified, old and serious, or light-hearted, young and cheery. @TeX{} is freely distributable. It is written in a superset of Pascal called WEB and can be compiled either in Pascal or (by using a conversion program that comes with the @TeX{} distribution) in C. (@xref{TeX Mode, ,@TeX{} Mode, emacs, The GNU Emacs Manual}, for information about @TeX{}.)@refill @TeX{} is very powerful and has a great many features. Because a Texinfo file must be able to present information both on a character-only terminal in Info form and in a typeset book, the formatting commands that Texinfo supports are necessarily limited. To get a copy of @TeX{}, see @ref{Obtaining TeX, , How to Obtain @TeX{}}. @node Formatting Commands @section @@-commands @cindex @@-commands @cindex Formatting commands In a Texinfo file, the commands that tell @TeX{} how to typeset the printed manual and tell @code{makeinfo} and @code{texinfo-format-buffer} how to create an Info file are preceded by @samp{@@}; they are called @dfn{@@-commands}. For example, @code{@@node} is the command to indicate a node and @code{@@chapter} is the command to indicate the start of a chapter.@refill @quotation Note Almost all @@ command names are entirely lower case. @end quotation The Texinfo @@-commands are a strictly limited set of constructs. The strict limits make it possible for Texinfo files to be understood both by @TeX{} and by the code that converts them into Info files. You can display Info files on any terminal that displays alphabetic and numeric characters. Similarly, you can print the output generated by @TeX{} on a wide variety of printers.@refill Depending on what they do or what arguments@footnote{The word @dfn{argument} comes from the way it is used in mathematics and does not refer to a dispute between two people; it refers to the information presented to the command. According to the @cite{Oxford English Dictionary}, the word derives from the Latin for @dfn{to make clear, prove}; thus it came to mean `the evidence offered as proof', which is to say, `the information offered', which led to its mathematical meaning. In its other thread of derivation, the word came to mean `to assert in a manner against which others may make counter assertions', which led to the meaning of `argument' as a dispute.} they take, you need to write @@-commands on lines of their own or as part of sentences: @itemize @bullet @item Write a command such as @code{@@quotation} at the beginning of a line as the only text on the line. (@code{@@quotation} begins an indented environment.) @item Write a command such as @code{@@chapter} at the beginning of a line followed by the command's arguments, in this case the chapter title, on the rest of the line. (@code{@@chapter} creates chapter titles.)@refill @item Write a command such as @code{@@dots@{@}} wherever you wish but usually within a sentence. (@code{@@dots@{@}} creates dots @dots{})@refill @item Write a command such as @code{@@code@{@var{sample-code}@}} wherever you wish (but usually within a sentence) with its argument, @var{sample-code} in this example, between the braces. (@code{@@code} marks text as being code.)@refill @item Write a command such as @code{@@example} on a line of its own; write the body-text on following lines; and write the matching @code{@@end} command, @code{@@end example} in this case, on a line of its own after the body-text. (@code{@@example} @dots{} @code{@@end example} indents and typesets body-text as an example.) It's usually ok to indent environment commands like this, but in complicated and hard-to-define circumstances the extra spaces cause extra space to appear in the output, so beware. @end itemize @noindent @cindex Braces, when to use As a general rule, a command requires braces if it mingles among other text; but it does not need braces if it starts a line of its own. The non-alphabetic commands, such as @code{@@:}, are exceptions to the rule; they do not need braces.@refill As you gain experience with Texinfo, you will rapidly learn how to write the different commands: the different ways to write commands actually make it easier to write and read Texinfo files than if all commands followed exactly the same syntax. @xref{Command Syntax, , @@-Command Syntax}, for all the details. @node Conventions @section General Syntactic Conventions @cindex General syntactic conventions @cindex Syntactic conventions @cindex Conventions, syntactic @cindex Characters, basic input This section describes the general conventions used in all Texinfo documents. @itemize @bullet @item @cindex Source files, characters used All printable @sc{ascii} characters except @samp{@@}, @samp{@{} and @samp{@}} can appear in a Texinfo file and stand for themselves. @samp{@@} is the escape character which introduces commands, while @samp{@{} and @samp{@}} are used to surround arguments to certain commands. To put one of these special characters into the document, put an @samp{@@} character in front of it, like this: @samp{@@@@}, @samp{@@@{}, and @samp{@@@}}. @item @cindex Paragraph separator @cindex Blank lines, as paragraph separator @cindex Newlines, as blank lines Separate paragraphs with one or more blank lines. Currently Texinfo only recognizes newline characters as end of line, not the CRLF sequence used on some systems; so a @dfn{blank line} means exactly two consecutive newlines. Sometimes blank lines are useful or convenient in other cases as well; you can use the @code{@@noindent} to inhibit paragraph indentation if required (@pxref{noindent,,@code{@@noindent}}). @item @cindex Quotation characters (`'), in source Use doubled single-quote characters to begin and end quotations: @w{@t{`@w{}`@dots{}'@w{}'}}. @TeX{} converts two single quotes to left- and right-hand doubled quotation marks, @c this comes out as "like this" in Info, which is just confusing. @iftex ``like this'', @end iftex and Info converts doubled single-quote characters to @sc{ascii} double-quotes: @w{@t{`@w{}`@dots{}'@w{}'}} becomes @w{@t{"@dots{}"}}. You may occasionally need to produce two consecutive single quotes; for example, in documenting a computer language such as Maxima where @t{'@w{}'} is a valid command. You can do this with the input @t{'@@w@{@}'}; the empty @code{@@w} command stops the combination into the double-quote characters. @cindex Unicode quotation characters @cindex Grave accent, vs.@: left quote The left quote character (@t{`}, ASCII code 96) used in Texinfo is a grave accent in ANSI and ISO character set standards. We use it as a quote character because that is how @TeX{} is set up, by default. We hope to eventually support the various quotation characters in Unicode. @item @cindex Multiple dashes in source @cindex Dashes in source @cindex Hyphens in source, two or three in a row @cindex Em dash, producing @cindex En dash, producing Use three hyphens in a row, @samp{---}, to produce a long dash---like this (called an @dfn{em dash}), used for punctuation in sentences. Use two hyphens, @samp{--}, to produce a medium dash (called an @dfn{en dash}), used primarily for numeric ranges, as in ``June 25--26''. Use a single hyphen, @samp{-}, to produce a standard hyphen used in compound words. For display on the screen, Info reduces three hyphens to two and two hyphens to one (not transitively!). Of course, any number of hyphens in the source remain as they are in literal contexts, such as @code{@@code} and @code{@@example}. @item @cindex Tabs; don't use! @strong{Caution:} Last and most important, do not use tab characters in a Texinfo file (except in verbatim modes)! @TeX{} uses variable-width fonts, which means that it is impractical at best to define a tab to work in all circumstances. Consequently, @TeX{} treats tabs like single spaces, and that is not what they look like in the source. Furthermore, @code{makeinfo} does nothing special with tabs, and thus a tab character in your input file will usually appear differently in the output. @noindent To avoid this problem, Texinfo mode causes GNU Emacs to insert multiple spaces when you press the @key{TAB} key. @noindent Also, you can run @code{untabify} in Emacs to convert tabs in a region to multiple spaces, or use the @code{unexpand} command from the shell. @end itemize @node Comments @section Comments @cindex Comments @findex comment @findex c @r{(comment)} You can write comments in a Texinfo file that will not appear in either the Info file or the printed manual by using the @code{@@comment} command (which may be abbreviated to @code{@@c}). Such comments are for the person who revises the Texinfo file. All the text on a line that follows either @code{@@comment} or @code{@@c} is a comment; the rest of the line does not appear in either the Info file or the printed manual. Often, you can write the @code{@@comment} or @code{@@c} in the middle of a line, and only the text that follows after the @code{@@comment} or @code{@@c} command does not appear; but some commands, such as @code{@@settitle} and @code{@@setfilename}, work on a whole line. You cannot use @code{@@comment} or @code{@@c} in a line beginning with such a command. @cindex Ignored text @cindex Unprocessed text @findex ignore You can write long stretches of text that will not appear in either the Info file or the printed manual by using the @code{@@ignore} and @code{@@end ignore} commands. Write each of these commands on a line of its own, starting each command at the beginning of the line. Text between these two commands does not appear in the processed output. You can use @code{@@ignore} and @code{@@end ignore} for writing comments. Text enclosed by @code{@@ignore} or by failing @code{@@ifset} or @code{@@ifclear} conditions is ignored in the sense that it will not contribute to the formatted output. However, @TeX{} and makeinfo must still parse the ignored text, in order to understand when to @emph{stop} ignoring text from the source file; that means that you may still get error messages if you have invalid Texinfo commands within ignored text. @node Minimum @section What a Texinfo File Must Have @cindex Minimal Texinfo file (requirements) @cindex Must have in Texinfo file @cindex Required in Texinfo file @cindex Texinfo file minimum By convention, the namea of a Texinfo file ends with (in order of preference) one of the extensions @file{.texinfo}, @file{.texi}, @file{.txi}, or @file{.tex}. The longer extensions are preferred since they describe more clearly to a human reader the nature of the file. The shorter extensions are for operating systems that cannot handle long file names. In order to be made into a printed manual and an Info file, a Texinfo file @strong{must} begin with lines like this: @example @group \input texinfo @@setfilename @var{info-file-name} @@settitle @var{name-of-manual} @end group @end example @noindent The contents of the file follow this beginning, and then you @strong{must} end a Texinfo file with a line like this: @example @@bye @end example @findex \input @r{(raw @TeX{} startup)} @noindent Here's an explanation: @itemize @bullet @item The @samp{\input texinfo} line tells @TeX{} to use the @file{texinfo.tex} file, which tells @TeX{} how to translate the Texinfo @@-commands into @TeX{} typesetting commands. (Note the use of the backslash, @samp{\}; this is correct for @TeX{}.) @item The @code{@@setfilename} line provides a name for the Info file and tells @TeX{} to open auxiliary files. @strong{All text before @code{@@setfilename} is ignored!} @item The @code{@@settitle} line specifies a title for the page headers (or footers) of the printed manual, and the default document description for the @samp{} in HTML format. Strictly speaking, @code{@@settitle} is optional---if you don't mind your document being titled `Untitled'. @item The @code{@@bye} line at the end of the file on a line of its own tells the formatters that the file is ended and to stop formatting. @end itemize Typically, you will not use quite such a spare format, but will include mode setting and start-of-header and end-of-header lines at the beginning of a Texinfo file, like this: @example @group \input texinfo @@c -*-texinfo-*- @@c %**start of header @@setfilename @var{info-file-name} @@settitle @var{name-of-manual} @@c %**end of header @end group @end example @noindent In the first line, @samp{-*-texinfo-*-} causes Emacs to switch into Texinfo mode when you edit the file. The @code{@@c} lines which surround the @code{@@setfilename} and @code{@@settitle} lines are optional, but you need them in order to run @TeX{} or Info on just part of the file. (@xref{Start of Header}.) Furthermore, you will usually provide a Texinfo file with a title page, indices, and the like, all of which are explained in this manual. But the minimum, which can be useful for short documents, is just the three lines at the beginning and the one line at the end. @node Six Parts @section Six Parts of a Texinfo File Generally, a Texinfo file contains more than the minimal beginning and end described in the previous section---it usually contains the six parts listed below. These are described fully in the following sections. @table @r @item 1. Header The @dfn{Header} names the file, tells @TeX{} which definitions file to use, and other such housekeeping tasks. @item 2. Summary and Copyright The @dfn{Summary and Copyright} segment describes the document and contains the copyright notice and copying permissions. This is done with the @code{@@copying} command. @item 3. Title and Copyright The @dfn{Title and Copyright} segment contains the title and copyright pages for the printed manual. The segment must be enclosed between @code{@@titlepage} and @code{@@end titlepage} commands. The title and copyright page appear only in the printed manual. @item 4. `Top' Node and Master Menu The `Top' node starts off the online output; it does not appear in the printed manual. We recommend including the copying permissions here as well as the segments above. And it contains at least a top-level menu listing the chapters, and possibly a @dfn{Master Menu} listing all the nodes in the entire document. @item 5. Body The @dfn{Body} of the document is typically structured like a traditional book or encyclopedia, but it may be free form. @item 6. End The @dfn{End} segment contains commands for printing indices and generating the table of contents, and the @code{@@bye} command on a line of its own. @end table @node Short Sample @section A Short Sample Texinfo File @cindex Sample Texinfo file, with comments Here is a very short but complete Texinfo file, in the six conventional parts enumerated in the previous section, so you can see how Texinfo source appears in practice. The first three parts of the file, from @samp{\input texinfo} through to @samp{@@end titlepage}, look more intimidating than they are: most of the material is standard boilerplate; when writing a manual, you simply change the names as appropriate. @xref{Beginning a File}, for full documentation on the commands listed here. @xref{GNU Sample Texts}, for the full texts to be used in GNU manuals. In the following, the sample text is @emph{indented}; comments on it are not. The complete file, without interspersed comments, is shown in @ref{Short Sample Texinfo File}. @subheading Part 1: Header @noindent The header does not appear in either the Info file or the printed output. It sets various parameters, including the name of the Info file and the title used in the header. @example @group \input texinfo @@c -*-texinfo-*- @@c %**start of header @@setfilename sample.info @@settitle Sample Manual 1.0 @@c %**end of header @end group @end example @subheading Part 2: Summary Description and Copyright @noindent A real manual includes more text here, according to the license under which it is distributed. @xref{GNU Sample Texts}. @example @group @@copying This is a short example of a complete Texinfo file, version 1.0. Copyright @@copyright@{@} 2004 Free Software Foundation, Inc. @@end copying @end group @end example @subheading Part 3: Titlepage, Contents, Copyright @noindent The titlepage segment does not appear in the online output, only in the printed manual. We use the @code{@@insertcopying} command to include the permission text from the previous section, instead of writing it out again; it is output on the back of the title page. The @code{@@contents} command generates a table of contents. @example @group @@titlepage @@title Sample Title @end group @group @@c The following two commands start the copyright page. @@page @@vskip 0pt plus 1filll @@insertcopying @@end titlepage @end group @@c Output the table of contents at the beginning. @@contents @end example @subheading Part 4: `Top' Node and Master Menu @noindent The `Top' node contains the master menu for the Info file. Since the printed manual uses a table of contents rather than a menu, it excludes the `Top' node. We also include the copying text again for the benefit of online readers. Since the copying text begins with a brief description of the manual, no other text is needed in this case. The @samp{@@top} command itself helps @command{makeinfo} determine the relationships between nodes. @example @@ifnottex @@node Top @@top Short Sample @@insertcopying @@end ifnottex @group @@menu * First Chapter:: The first chapter is the only chapter in this sample. * Index:: Complete index. @@end menu @end group @end example @subheading Part 5: The Body of the Document @noindent The body segment contains all the text of the document, but not the indices or table of contents. This example illustrates a node and a chapter containing an enumerated list. @example @group @@node First Chapter @@chapter First Chapter @@cindex chapter, first @end group @group This is the first chapter. @@cindex index entry, another @end group @group Here is a numbered list. @@enumerate @@item This is the first item. @@item This is the second item. @@end enumerate @end group @end example @subheading Part 6: The End of the Document @noindent The end segment contains commands for generating an index in a node and unnumbered chapter of its own, and the @code{@@bye} command that marks the end of the document. @example @group @@node Index @@unnumbered Index @end group @group @@printindex cp @@bye @end group @end example @subheading Some Results Here is what the contents of the first chapter of the sample look like: @sp 1 @need 700 @quotation This is the first chapter. Here is a numbered list. @enumerate @item This is the first item. @item This is the second item. @end enumerate @end quotation @node History @section History @cindex Stallman, Richard M. @cindex Chassell, Robert J. @cindex Fox, Brian @cindex Berry, Karl Richard M.@: Stallman invented the Texinfo format, wrote the initial processors, and created Edition 1.0 of this manual. @w{Robert J.@:} Chassell greatly revised and extended the manual, starting with Edition 1.1. Brian Fox was responsible for the standalone Texinfo distribution until version 3.8, and wrote the standalone @command{makeinfo} and @command{info} programs. Karl Berry has continued maintenance since Texinfo 3.8 (manual edition 2.22). @cindex Pinard, Fran@,{c}ois @cindex Zuhn, David D. @cindex Weisshaus, Melissa @cindex Zaretskii, Eli @cindex Schwab, Andreas @cindex Weinberg, Zack Our thanks go out to all who helped improve this work, particularly the indefatigable Eli Zaretskii and Andreas Schwab, who have provided patches beyond counting. Fran@,{c}ois Pinard and @w{David D.@: Zuhn}, tirelessly recorded and reported mistakes and obscurities. Zack Weinberg did the impossible by implementing the macro syntax in @file{texinfo.tex}. Special thanks go to Melissa Weisshaus for her frequent reviews of nearly similar editions. Dozens of others have contributed patches and suggestions, they are gratefully acknowledged in the @file{ChangeLog} file. Our mistakes are our own. @cindex Scribe @cindex Reid, Brian @cindex History of Texinfo @cindex Texinfo history A bit of history: in the 1970's at CMU, Brian Reid developed a program and format named Scribe to mark up documents for printing. It used the @code{@@} character to introduce commands, as Texinfo does. Much more consequentially, it strived to describe document contents rather than formatting, an idea wholeheartedly adopted by Texinfo. @cindex Bolio @cindex Bo@TeX{} Meanwhile, people at MIT developed another, not too dissimilar format called Bolio. This then was converted to using @TeX{} as its typesetting language: Bo@TeX{}. The earliest Bo@TeX{} version seems to have been 0.02 on October 31, 1984. Bo@TeX{} could only be used as a markup language for documents to be printed, not for online documents. Richard Stallman (RMS) worked on both Bolio and Bo@TeX{}. He also developed a nifty on-line help format called Info, and then combined Bo@TeX{} and Info to create Texinfo, a mark up language for text that is intended to be read both online and as printed hard copy. @node Texinfo Mode @chapter Using Texinfo Mode @cindex Texinfo mode @cindex Mode, using Texinfo @cindex GNU Emacs @cindex Emacs You may edit a Texinfo file with any text editor you choose. A Texinfo file is no different from any other @sc{ascii} file. However, GNU Emacs comes with a special mode, called Texinfo mode, that provides Emacs commands and tools to help ease your work. This chapter describes features of GNU Emacs' Texinfo mode but not any features of the Texinfo formatting language. So if you are reading this manual straight through from the beginning, you may want to skim through this chapter briefly and come back to it after reading succeeding chapters which describe the Texinfo formatting language in detail. @menu * Texinfo Mode Overview:: How Texinfo mode can help you. * Emacs Editing:: Texinfo mode adds to GNU Emacs' general purpose editing features. * Inserting:: How to insert frequently used @@-commands. * Showing the Structure:: How to show the structure of a file. * Updating Nodes and Menus:: How to update or create new nodes and menus. * Info Formatting:: How to format for Info. * Printing:: How to format and print part or all of a file. * Texinfo Mode Summary:: Summary of all the Texinfo mode commands. @end menu @node Texinfo Mode Overview @section Texinfo Mode Overview Texinfo mode provides special features for working with Texinfo files. You can: @itemize @bullet @item Insert frequently used @@-commands. @refill @item Automatically create @code{@@node} lines. @item Show the structure of a Texinfo source file.@refill @item Automatically create or update the `Next', `Previous', and `Up' pointers of a node. @item Automatically create or update menus.@refill @item Automatically create a master menu.@refill @item Format a part or all of a file for Info.@refill @item Typeset and print part or all of a file.@refill @end itemize Perhaps the two most helpful features are those for inserting frequently used @@-commands and for creating node pointers and menus.@refill @node Emacs Editing @section The Usual GNU Emacs Editing Commands In most cases, the usual Text mode commands work the same in Texinfo mode as they do in Text mode. Texinfo mode adds new editing commands and tools to GNU Emacs' general purpose editing features. The major difference concerns filling. In Texinfo mode, the paragraph separation variable and syntax table are redefined so that Texinfo commands that should be on lines of their own are not inadvertently included in paragraphs. Thus, the @kbd{M-q} (@code{fill-paragraph}) command will refill a paragraph but not mix an indexing command on a line adjacent to it into the paragraph.@refill In addition, Texinfo mode sets the @code{page-delimiter} variable to the value of @code{texinfo-chapter-level-regexp}; by default, this is a regular expression matching the commands for chapters and their equivalents, such as appendices. With this value for the page delimiter, you can jump from chapter title to chapter title with the @kbd{C-x ]} (@code{forward-page}) and @kbd{C-x [} (@code{backward-page}) commands and narrow to a chapter with the @kbd{C-x p} (@code{narrow-to-page}) command. (@xref{Pages, , ,emacs, The GNU Emacs Manual}, for details about the page commands.)@refill You may name a Texinfo file however you wish, but the convention is to end a Texinfo file name with one of the extensions @file{.texinfo}, @file{.texi}, @file{.txi}, or @file{.tex}. A longer extension is preferred, since it is explicit, but a shorter extension may be necessary for operating systems that limit the length of file names. GNU Emacs automatically enters Texinfo mode when you visit a file with a @file{.texinfo}, @file{.texi} or @file{.txi} extension. Also, Emacs switches to Texinfo mode when you visit a file that has @samp{-*-texinfo-*-} in its first line. If ever you are in another mode and wish to switch to Texinfo mode, type @code{M-x texinfo-mode}.@refill Like all other Emacs features, you can customize or enhance Texinfo mode as you wish. In particular, the keybindings are very easy to change. The keybindings described here are the default or standard ones.@refill @node Inserting @comment node-name, next, previous, up @section Inserting Frequently Used Commands @cindex Inserting frequently used commands @cindex Frequently used commands, inserting @cindex Commands, inserting them Texinfo mode provides commands to insert various frequently used @@-commands into the buffer. You can use these commands to save keystrokes.@refill The insert commands are invoked by typing @kbd{C-c} twice and then the first letter of the @@-command:@refill @table @kbd @item C-c C-c c @itemx M-x texinfo-insert-@@code @findex texinfo-insert-@@code Insert @code{@@code@{@}} and put the cursor between the braces.@refill @item C-c C-c d @itemx M-x texinfo-insert-@@dfn @findex texinfo-insert-@@dfn Insert @code{@@dfn@{@}} and put the cursor between the braces.@refill @item C-c C-c e @itemx M-x texinfo-insert-@@end @findex texinfo-insert-@@end Insert @code{@@end} and attempt to insert the correct following word, such as @samp{example} or @samp{table}. (This command does not handle nested lists correctly, but inserts the word appropriate to the immediately preceding list.)@refill @item C-c C-c i @itemx M-x texinfo-insert-@@item @findex texinfo-insert-@@item Insert @code{@@item} and put the cursor at the beginning of the next line.@refill @item C-c C-c k @itemx M-x texinfo-insert-@@kbd @findex texinfo-insert-@@kbd Insert @code{@@kbd@{@}} and put the cursor between the braces.@refill @item C-c C-c n @itemx M-x texinfo-insert-@@node @findex texinfo-insert-@@node Insert @code{@@node} and a comment line listing the sequence for the `Next', `Previous', and `Up' nodes. Leave point after the @code{@@node}.@refill @item C-c C-c o @itemx M-x texinfo-insert-@@noindent @findex texinfo-insert-@@noindent Insert @code{@@noindent} and put the cursor at the beginning of the next line.@refill @item C-c C-c s @itemx M-x texinfo-insert-@@samp @findex texinfo-insert-@@samp Insert @code{@@samp@{@}} and put the cursor between the braces.@refill @item C-c C-c t @itemx M-x texinfo-insert-@@table @findex texinfo-insert-@@table Insert @code{@@table} followed by a @key{SPC} and leave the cursor after the @key{SPC}.@refill @item C-c C-c v @itemx M-x texinfo-insert-@@var @findex texinfo-insert-@@var Insert @code{@@var@{@}} and put the cursor between the braces.@refill @item C-c C-c x @itemx M-x texinfo-insert-@@example @findex texinfo-insert-@@example Insert @code{@@example} and put the cursor at the beginning of the next line.@refill @c M-@{ was the binding for texinfo-insert-braces; @c in Emacs 19, backward-paragraph will take this binding. @item C-c C-c @{ @itemx M-x texinfo-insert-braces @findex texinfo-insert-braces Insert @code{@{@}} and put the cursor between the braces.@refill @item C-c C-c @} @itemx C-c C-c ] @itemx M-x up-list @findex up-list Move from between a pair of braces forward past the closing brace. Typing @kbd{C-c C-c ]} is easier than typing @kbd{C-c C-c @}}, which is, however, more mnemonic; hence the two keybindings. (Also, you can move out from between braces by typing @kbd{C-f}.)@refill @end table To put a command such as @w{@code{@@code@{@dots{}@}}} around an @emph{existing} word, position the cursor in front of the word and type @kbd{C-u 1 C-c C-c c}. This makes it easy to edit existing plain text. The value of the prefix argument tells Emacs how many words following point to include between braces---@samp{1} for one word, @samp{2} for two words, and so on. Use a negative argument to enclose the previous word or words. If you do not specify a prefix argument, Emacs inserts the @@-command string and positions the cursor between the braces. This feature works only for those @@-commands that operate on a word or words within one line, such as @code{@@kbd} and @code{@@var}.@refill This set of insert commands was created after analyzing the frequency with which different @@-commands are used in the @cite{GNU Emacs Manual} and the @cite{GDB Manual}. If you wish to add your own insert commands, you can bind a keyboard macro to a key, use abbreviations, or extend the code in @file{texinfo.el}.@refill @findex texinfo-start-menu-description @cindex Menu description, start @cindex Description for menu, start @kbd{C-c C-c C-d} (@code{texinfo-start-menu-description}) is an insert command that works differently from the other insert commands. It inserts a node's section or chapter title in the space for the description in a menu entry line. (A menu entry has three parts, the entry name, the node name, and the description. Only the node name is required, but a description helps explain what the node is about. @xref{Menu Parts, , The Parts of a Menu}.)@refill To use @code{texinfo-start-menu-description}, position point in a menu entry line and type @kbd{C-c C-c C-d}. The command looks for and copies the title that goes with the node name, and inserts the title as a description; it positions point at beginning of the inserted text so you can edit it. The function does not insert the title if the menu entry line already contains a description.@refill This command is only an aid to writing descriptions; it does not do the whole job. You must edit the inserted text since a title tends to use the same words as a node name but a useful description uses different words.@refill @node Showing the Structure @comment node-name, next, previous, up @section Showing the Section Structure of a File @cindex Showing the section structure of a file @cindex Section structure of a file, showing it @cindex Structure of a file, showing it @cindex Outline of file structure, showing it @cindex Contents-like outline of file structure @cindex File section structure, showing it @cindex Texinfo file section structure, showing it You can show the section structure of a Texinfo file by using the @kbd{C-c C-s} command (@code{texinfo-show-structure}). This command shows the section structure of a Texinfo file by listing the lines that begin with the @@-commands for @code{@@chapter}, @code{@@section}, and the like. It constructs what amounts to a table of contents. These lines are displayed in another buffer called the @samp{*Occur*} buffer. In that buffer, you can position the cursor over one of the lines and use the @kbd{C-c C-c} command (@code{occur-mode-goto-occurrence}), to jump to the corresponding spot in the Texinfo file.@refill @table @kbd @item C-c C-s @itemx M-x texinfo-show-structure @findex texinfo-show-structure Show the @code{@@chapter}, @code{@@section}, and such lines of a Texinfo file.@refill @item C-c C-c @itemx M-x occur-mode-goto-occurrence @findex occur-mode-goto-occurrence Go to the line in the Texinfo file corresponding to the line under the cursor in the @file{*Occur*} buffer.@refill @end table If you call @code{texinfo-show-structure} with a prefix argument by typing @w{@kbd{C-u C-c C-s}}, it will list not only those lines with the @@-commands for @code{@@chapter}, @code{@@section}, and the like, but also the @code{@@node} lines. You can use @code{texinfo-show-structure} with a prefix argument to check whether the `Next', `Previous', and `Up' pointers of an @code{@@node} line are correct. Often, when you are working on a manual, you will be interested only in the structure of the current chapter. In this case, you can mark off the region of the buffer that you are interested in by using the @kbd{C-x n n} (@code{narrow-to-region}) command and @code{texinfo-show-structure} will work on only that region. To see the whole buffer again, use @w{@kbd{C-x n w}} (@code{widen}). (@xref{Narrowing, , , emacs, The GNU Emacs Manual}, for more information about the narrowing commands.)@refill @vindex page-delimiter @cindex Page delimiter in Texinfo mode In addition to providing the @code{texinfo-show-structure} command, Texinfo mode sets the value of the page delimiter variable to match the chapter-level @@-commands. This enables you to use the @kbd{C-x ]} (@code{forward-page}) and @kbd{C-x [} (@code{backward-page}) commands to move forward and backward by chapter, and to use the @kbd{C-x p} (@code{narrow-to-page}) command to narrow to a chapter. @xref{Pages, , , emacs, The GNU Emacs Manual}, for more information about the page commands.@refill @node Updating Nodes and Menus @comment node-name, next, previous, up @section Updating Nodes and Menus @cindex Updating nodes and menus @cindex Create nodes, menus automatically @cindex Insert nodes, menus automatically @cindex Automatically insert nodes, menus Texinfo mode provides commands for automatically creating or updating menus and node pointers. The commands are called ``update'' commands because their most frequent use is for updating a Texinfo file after you have worked on it; but you can use them to insert the `Next', `Previous', and `Up' pointers into an @code{@@node} line that has none and to create menus in a file that has none. If you do not use the updating commands, you need to write menus and node pointers by hand, which is a tedious task.@refill @menu * Updating Commands:: Five major updating commands. * Updating Requirements:: How to structure a Texinfo file for using the updating command. * Other Updating Commands:: How to indent descriptions, insert missing nodes lines, and update nodes in sequence. @end menu @node Updating Commands @subsection The Updating Commands You can use the updating commands to:@refill @itemize @bullet @item insert or update the `Next', `Previous', and `Up' pointers of a node,@refill @item insert or update the menu for a section, and@refill @item create a master menu for a Texinfo source file.@refill @end itemize You can also use the commands to update all the nodes and menus in a region or in a whole Texinfo file.@refill The updating commands work only with conventional Texinfo files, which are structured hierarchically like books. In such files, a structuring command line must follow closely after each @code{@@node} line, except for the `Top' @code{@@node} line. (A @dfn{structuring command line} is a line beginning with @code{@@chapter}, @code{@@section}, or other similar command.) You can write the structuring command line on the line that follows immediately after an @code{@@node} line or else on the line that follows after a single @code{@@comment} line or a single @code{@@ifinfo} line. You cannot interpose more than one line between the @code{@@node} line and the structuring command line; and you may interpose only an @code{@@comment} line or an @code{@@ifinfo} line. Commands which work on a whole buffer require that the `Top' node be followed by a node with an @code{@@chapter} or equivalent-level command. The menu updating commands will not create a main or master menu for a Texinfo file that has only @code{@@chapter}-level nodes! The menu updating commands only create menus @emph{within} nodes for lower level nodes. To create a menu of chapters, you must provide a `Top' node. The menu updating commands remove menu entries that refer to other Info files since they do not refer to nodes within the current buffer. This is a deficiency. Rather than use menu entries, you can use cross references to refer to other Info files. None of the updating commands affect cross references.@refill Texinfo mode has five updating commands that are used most often: two are for updating the node pointers or menu of a single node (or a region); two are for updating every node pointer and menu in a file; and one, the @code{texinfo-master-menu} command, is for creating a master menu for a complete file, and optionally, for updating every node and menu in the whole Texinfo file.@refill The @code{texinfo-master-menu} command is the primary command:@refill @table @kbd @item C-c C-u m @itemx M-x texinfo-master-menu @findex texinfo-master-menu Create or update a master menu that includes all the other menus (incorporating the descriptions from pre-existing menus, if any).@refill With an argument (prefix argument, @kbd{C-u,} if interactive), first create or update all the nodes and all the regular menus in the buffer before constructing the master menu. (@xref{The Top Node, , The Top Node and Master Menu}, for more about a master menu.)@refill For @code{texinfo-master-menu} to work, the Texinfo file must have a `Top' node and at least one subsequent node.@refill After extensively editing a Texinfo file, you can type the following: @example C-u M-x texinfo-master-menu @exdent or C-u C-c C-u m @end example @noindent This updates all the nodes and menus completely and all at once.@refill @end table The other major updating commands do smaller jobs and are designed for the person who updates nodes and menus as he or she writes a Texinfo file.@refill @need 1000 The commands are:@refill @table @kbd @item C-c C-u C-n @itemx M-x texinfo-update-node @findex texinfo-update-node Insert the `Next', `Previous', and `Up' pointers for the node that point is within (i.e., for the @code{@@node} line preceding point). If the @code{@@node} line has pre-existing `Next', `Previous', or `Up' pointers in it, the old pointers are removed and new ones inserted. With an argument (prefix argument, @kbd{C-u}, if interactive), this command updates all @code{@@node} lines in the region (which is the text between point and mark).@refill @item C-c C-u C-m @itemx M-x texinfo-make-menu @findex texinfo-make-menu Create or update the menu in the node that point is within. With an argument (@kbd{C-u} as prefix argument, if interactive), the command makes or updates menus for the nodes which are either within or a part of the region.@refill Whenever @code{texinfo-make-menu} updates an existing menu, the descriptions from that menu are incorporated into the new menu. This is done by copying descriptions from the existing menu to the entries in the new menu that have the same node names. If the node names are different, the descriptions are not copied to the new menu.@refill @item C-c C-u C-e @itemx M-x texinfo-every-node-update @findex texinfo-every-node-update Insert or update the `Next', `Previous', and `Up' pointers for every node in the buffer.@refill @item C-c C-u C-a @itemx M-x texinfo-all-menus-update @findex texinfo-all-menus-update Create or update all the menus in the buffer. With an argument (@kbd{C-u} as prefix argument, if interactive), first insert or update all the node pointers before working on the menus.@refill If a master menu exists, the @code{texinfo-all-menus-update} command updates it; but the command does not create a new master menu if none already exists. (Use the @code{texinfo-master-menu} command for that.)@refill When working on a document that does not merit a master menu, you can type the following: @example C-u C-c C-u C-a @exdent or C-u M-x texinfo-all-menus-update @end example @noindent This updates all the nodes and menus.@refill @end table The @code{texinfo-column-for-description} variable specifies the column to which menu descriptions are indented. By default, the value is 32 although it is often useful to reduce it to as low as 24. You can set the variable via customization (@pxref{Changing an Option,,, emacs, The GNU Emacs Manual}) or with the @kbd{M-x set-variable} command (@pxref{Examining, , Examining and Setting Variables, emacs, The GNU Emacs Manual}). Also, the @code{texinfo-indent-menu-description} command may be used to indent existing menu descriptions to a specified column. Finally, if you wish, you can use the @code{texinfo-insert-node-lines} command to insert missing @code{@@node} lines into a file. (@xref{Other Updating Commands}, for more information.)@refill @node Updating Requirements @subsection Updating Requirements @cindex Updating requirements @cindex Requirements for updating commands To use the updating commands, you must organize the Texinfo file hierarchically with chapters, sections, subsections, and the like. When you construct the hierarchy of the manual, do not `jump down' more than one level at a time: you can follow the `Top' node with a chapter, but not with a section; you can follow a chapter with a section, but not with a subsection. However, you may `jump up' any number of levels at one time---for example, from a subsection to a chapter.@refill Each @code{@@node} line, with the exception of the line for the `Top' node, must be followed by a line with a structuring command such as @code{@@chapter}, @code{@@section}, or @code{@@unnumberedsubsec}.@refill Each @code{@@node} line/structuring-command line combination must look either like this: @example @group @@node Comments, Minimum, Conventions, Overview @@comment node-name, next, previous, up @@section Comments @end group @end example or like this (without the @code{@@comment} line): @example @group @@node Comments, Minimum, Conventions, Overview @@section Comments @end group @end example or like this (without the explicit node pointers): @example @group @@node Comments @@section Comments @end group @end example @noindent In this example, `Comments' is the name of both the node and the section. The next node is called `Minimum' and the previous node is called `Conventions'. The `Comments' section is within the `Overview' node, which is specified by the `Up' pointer. (Instead of an @code{@@comment} line, you may also write an @code{@@ifinfo} line.) If a file has a `Top' node, it must be called @samp{top} or @samp{Top} and be the first node in the file. The menu updating commands create a menu of sections within a chapter, a menu of subsections within a section, and so on. This means that you must have a `Top' node if you want a menu of chapters.@refill Incidentally, the @code{makeinfo} command will create an Info file for a hierarchically organized Texinfo file that lacks `Next', `Previous' and `Up' pointers. Thus, if you can be sure that your Texinfo file will be formatted with @code{makeinfo}, you have no need for the update node commands. (@xref{Creating an Info File}, for more information about @code{makeinfo}.) However, both @code{makeinfo} and the @code{texinfo-format-@dots{}} commands require that you insert menus in the file. @node Other Updating Commands @subsection Other Updating Commands In addition to the five major updating commands, Texinfo mode possesses several less frequently used updating commands:@refill @table @kbd @item M-x texinfo-insert-node-lines @findex texinfo-insert-node-lines Insert @code{@@node} lines before the @code{@@chapter}, @code{@@section}, and other sectioning commands wherever they are missing throughout a region in a Texinfo file.@refill With an argument (@kbd{C-u} as prefix argument, if interactive), the @code{texinfo-insert-node-lines} command not only inserts @code{@@node} lines but also inserts the chapter or section titles as the names of the corresponding nodes. In addition, it inserts the titles as node names in pre-existing @code{@@node} lines that lack names. Since node names should be more concise than section or chapter titles, you must manually edit node names so inserted.@refill For example, the following marks a whole buffer as a region and inserts @code{@@node} lines and titles throughout:@refill @example C-x h C-u M-x texinfo-insert-node-lines @end example This command inserts titles as node names in @code{@@node} lines; the @code{texinfo-start-menu-description} command (@pxref{Inserting, Inserting Frequently Used Commands}) inserts titles as descriptions in menu entries, a different action. However, in both cases, you need to edit the inserted text. @item M-x texinfo-multiple-files-update @findex texinfo-multiple-files-update @r{(in brief)} Update nodes and menus in a document built from several separate files. With @kbd{C-u} as a prefix argument, create and insert a master menu in the outer file. With a numeric prefix argument, such as @kbd{C-u 2}, first update all the menus and all the `Next', `Previous', and `Up' pointers of all the included files before creating and inserting a master menu in the outer file. The @code{texinfo-multiple-files-update} command is described in the appendix on @code{@@include} files. @xref{texinfo-multiple-files-update}. @item M-x texinfo-indent-menu-description @findex texinfo-indent-menu-description Indent every description in the menu following point to the specified column. You can use this command to give yourself more space for descriptions. With an argument (@kbd{C-u} as prefix argument, if interactive), the @code{texinfo-indent-menu-description} command indents every description in every menu in the region. However, this command does not indent the second and subsequent lines of a multi-line description.@refill @item M-x texinfo-sequential-node-update @findex texinfo-sequential-node-update Insert the names of the nodes immediately following and preceding the current node as the `Next' or `Previous' pointers regardless of those nodes' hierarchical level. This means that the `Next' node of a subsection may well be the next chapter. Sequentially ordered nodes are useful for novels and other documents that you read through sequentially. (However, in Info, the @kbd{g *} command lets you look through the file sequentially, so sequentially ordered nodes are not strictly necessary.) With an argument (prefix argument, if interactive), the @code{texinfo-sequential-node-update} command sequentially updates all the nodes in the region.@refill @end table @node Info Formatting @comment node-name, next, previous, up @section Formatting for Info @cindex Formatting for Info @cindex Running an Info formatter @cindex Info formatting Texinfo mode provides several commands for formatting part or all of a Texinfo file for Info. Often, when you are writing a document, you want to format only part of a file---that is, a region.@refill You can use either the @code{texinfo-format-region} or the @code{makeinfo-region} command to format a region:@refill @table @kbd @findex texinfo-format-region @item C-c C-e C-r @itemx M-x texinfo-format-region @itemx C-c C-m C-r @itemx M-x makeinfo-region Format the current region for Info.@refill @end table You can use either the @code{texinfo-format-buffer} or the @code{makeinfo-buffer} command to format a whole buffer:@refill @table @kbd @findex texinfo-format-buffer @item C-c C-e C-b @itemx M-x texinfo-format-buffer @itemx C-c C-m C-b @itemx M-x makeinfo-buffer Format the current buffer for Info.@refill @end table @need 1000 For example, after writing a Texinfo file, you can type the following: @example C-u C-c C-u m @exdent or C-u M-x texinfo-master-menu @end example @noindent This updates all the nodes and menus. Then type the following to create an Info file: @example C-c C-m C-b @exdent or M-x makeinfo-buffer @end example For @TeX{} or the Info formatting commands to work, the file @emph{must} include a line that has @code{@@setfilename} in its header. @xref{Creating an Info File}, for details about Info formatting.@refill @node Printing @comment node-name, next, previous, up @section Printing @cindex Formatting for printing @cindex Printing a region or buffer @cindex Region formatting and printing @cindex Buffer formatting and printing @cindex Part of file formatting and printing Typesetting and printing a Texinfo file is a multi-step process in which you first create a file for printing (called a DVI file), and then print the file. Optionally, you may also create indices. To do this, you must run the @code{texindex} command after first running the @code{tex} typesetting command; and then you must run the @code{tex} command again. Or else run the @code{texi2dvi} command which automatically creates indices as needed (@pxref{Format with texi2dvi}). Often, when you are writing a document, you want to typeset and print only part of a file to see what it will look like. You can use the @code{texinfo-tex-region} and related commands for this purpose. Use the @code{texinfo-tex-buffer} command to format all of a buffer.@refill @table @kbd @item C-c C-t C-b @itemx M-x texinfo-tex-buffer @findex texinfo-tex-buffer Run @code{texi2dvi} on the buffer. In addition to running @TeX{} on the buffer, this command automatically creates or updates indices as needed.@refill @item C-c C-t C-r @itemx M-x texinfo-tex-region @findex texinfo-tex-region Run @TeX{} on the region.@refill @item C-c C-t C-i @itemx M-x texinfo-texindex Run @code{texindex} to sort the indices of a Texinfo file formatted with @code{texinfo-tex-region}. The @code{texinfo-tex-region} command does not run @code{texindex} automatically; it only runs the @code{tex} typesetting command. You must run the @code{texinfo-tex-region} command a second time after sorting the raw index files with the @code{texindex} command. (Usually, you do not format an index when you format a region, only when you format a buffer. Now that the @code{texi2dvi} command exists, there is little or no need for this command.)@refill @item C-c C-t C-p @itemx M-x texinfo-tex-print @findex texinfo-tex-print Print the file (or the part of the file) previously formatted with @code{texinfo-tex-buffer} or @code{texinfo-tex-region}.@refill @end table For @code{texinfo-tex-region} or @code{texinfo-tex-buffer} to work, the file @emph{must} start with a @samp{\input texinfo} line and must include an @code{@@settitle} line. The file must end with @code{@@bye} on a line by itself. (When you use @code{texinfo-tex-region}, you must surround the @code{@@settitle} line with start-of-header and end-of-header lines.)@refill @xref{Hardcopy}, for a description of the other @TeX{} related commands, such as @code{tex-show-print-queue}.@refill @node Texinfo Mode Summary @comment node-name, next, previous, up @section Texinfo Mode Summary In Texinfo mode, each set of commands has default keybindings that begin with the same keys. All the commands that are custom-created for Texinfo mode begin with @kbd{C-c}. The keys are somewhat mnemonic.@refill @subheading Insert Commands The insert commands are invoked by typing @kbd{C-c} twice and then the first letter of the @@-command to be inserted. (It might make more sense mnemonically to use @kbd{C-c C-i}, for `custom insert', but @kbd{C-c C-c} is quick to type.)@refill @example C-c C-c c @r{Insert} @samp{@@code}. C-c C-c d @r{Insert} @samp{@@dfn}. C-c C-c e @r{Insert} @samp{@@end}. C-c C-c i @r{Insert} @samp{@@item}. C-c C-c n @r{Insert} @samp{@@node}. C-c C-c s @r{Insert} @samp{@@samp}. C-c C-c v @r{Insert} @samp{@@var}. C-c C-c @{ @r{Insert braces.} C-c C-c ] C-c C-c @} @r{Move out of enclosing braces.} @group C-c C-c C-d @r{Insert a node's section title} @r{in the space for the description} @r{in a menu entry line.} @end group @end example @subheading Show Structure The @code{texinfo-show-structure} command is often used within a narrowed region.@refill @example C-c C-s @r{List all the headings.} @end example @subheading The Master Update Command The @code{texinfo-master-menu} command creates a master menu; and can be used to update every node and menu in a file as well.@refill @c Probably should use @tables in this section. @example @group C-c C-u m M-x texinfo-master-menu @r{Create or update a master menu.} @end group @group C-u C-c C-u m @r{With @kbd{C-u} as a prefix argument, first} @r{create or update all nodes and regular} @r{menus, and then create a master menu.} @end group @end example @subheading Update Pointers The update pointer commands are invoked by typing @kbd{C-c C-u} and then either @kbd{C-n} for @code{texinfo-update-node} or @kbd{C-e} for @code{texinfo-every-node-update}.@refill @example C-c C-u C-n @r{Update a node.} C-c C-u C-e @r{Update every node in the buffer.} @end example @subheading Update Menus Invoke the update menu commands by typing @kbd{C-c C-u} and then either @kbd{C-m} for @code{texinfo-make-menu} or @kbd{C-a} for @code{texinfo-all-menus-update}. To update both nodes and menus at the same time, precede @kbd{C-c C-u C-a} with @kbd{C-u}.@refill @example C-c C-u C-m @r{Make or update a menu.} @group C-c C-u C-a @r{Make or update all} @r{menus in a buffer.} @end group @group C-u C-c C-u C-a @r{With @kbd{C-u} as a prefix argument,} @r{first create or update all nodes and} @r{then create or update all menus.} @end group @end example @subheading Format for Info The Info formatting commands that are written in Emacs Lisp are invoked by typing @kbd{C-c C-e} and then either @kbd{C-r} for a region or @kbd{C-b} for the whole buffer.@refill The Info formatting commands that are written in C and based on the @code{makeinfo} program are invoked by typing @kbd{C-c C-m} and then either @kbd{C-r} for a region or @kbd{C-b} for the whole buffer.@refill @need 800 @noindent Use the @code{texinfo-format@dots{}} commands: @example @group C-c C-e C-r @r{Format the region.} C-c C-e C-b @r{Format the buffer.} @end group @end example @need 750 @noindent Use @code{makeinfo}: @example C-c C-m C-r @r{Format the region.} C-c C-m C-b @r{Format the buffer.} C-c C-m C-l @r{Recenter the @code{makeinfo} output buffer.} C-c C-m C-k @r{Kill the @code{makeinfo} formatting job.} @end example @subheading Typeset and Print The @TeX{} typesetting and printing commands are invoked by typing @kbd{C-c C-t} and then another control command: @kbd{C-r} for @code{texinfo-tex-region}, @kbd{C-b} for @code{texinfo-tex-buffer}, and so on.@refill @example C-c C-t C-r @r{Run @TeX{} on the region.} C-c C-t C-b @r{Run} @code{texi2dvi} @r{on the buffer.} C-c C-t C-i @r{Run} @code{texindex}. C-c C-t C-p @r{Print the DVI file.} C-c C-t C-q @r{Show the print queue.} C-c C-t C-d @r{Delete a job from the print queue.} C-c C-t C-k @r{Kill the current @TeX{} formatting job.} C-c C-t C-x @r{Quit a currently stopped @TeX{} formatting job.} C-c C-t C-l @r{Recenter the output buffer.} @end example @subheading Other Updating Commands The remaining updating commands do not have standard keybindings because they are rarely used. @example @group M-x texinfo-insert-node-lines @r{Insert missing @code{@@node} lines in region.} @r{With @kbd{C-u} as a prefix argument,} @r{use section titles as node names.} @end group @group M-x texinfo-multiple-files-update @r{Update a multi-file document.} @r{With @kbd{C-u 2} as a prefix argument,} @r{create or update all nodes and menus} @r{in all included files first.} @end group @group M-x texinfo-indent-menu-description @r{Indent descriptions.} @end group @group M-x texinfo-sequential-node-update @r{Insert node pointers in strict sequence.} @end group @end example @node Beginning a File @chapter Beginning a Texinfo File @cindex Beginning a Texinfo file @cindex Texinfo file beginning @cindex File beginning Certain pieces of information must be provided at the beginning of a Texinfo file, such as the name for the output file(s), the title of the document, and the Top node. A table of contents is also generally produced here. This chapter expands on the minimal complete Texinfo source file previously given (@pxref{Six Parts}). It describes the numerous commands for handling the traditional frontmatter items in Texinfo. @cindex Frontmatter, text in Straight text outside of any command before the Top node should be avoided. Such text is treated differently in the different output formats: visible in @TeX{} and HTML, by default not shown in Info readers, and so on. @menu * Sample Beginning:: A sample beginning for a Texinfo file. * Texinfo File Header:: The first lines. * Document Permissions:: Ensuring your manual is free. * Titlepage & Copyright Page:: Creating the title and copyright pages. * Contents:: How to create a table of contents. * The Top Node:: Creating the `Top' node and master menu. * Global Document Commands:: Affecting formatting throughout. * Software Copying Permissions:: Ensure that you and others continue to have the right to use and share software. @end menu @node Sample Beginning @section Sample Texinfo File Beginning @cindex Example beginning of Texinfo file The following sample shows what is needed. The elements given here are explained in more detail in the following sections. Other commands are often included at the beginning of Texinfo files, but the ones here are the most critical. @xref{GNU Sample Texts}, for the full texts to be used in GNU manuals. @example \input texinfo @@c -*-texinfo-*- @@c %**start of header @@setfilename @var{infoname}.info @@settitle @var{name-of-manual} @var{version} @@c %**end of header @@copying This manual is for @var{program}, version @var{version}. Copyright @@copyright@{@} @var{years} @var{copyright-owner}. @group @@quotation Permission is granted to @dots{} @@end quotation @@end copying @end group @group @@titlepage @@title @var{name-of-manual-when-printed} @@subtitle @var{subtitle-if-any} @@subtitle @var{second-subtitle} @@author @var{author} @end group @group @@c The following two commands @@c start the copyright page. @@page @@vskip 0pt plus 1filll @@insertcopying @end group Published by @dots{} @@end titlepage @@c So the toc is printed at the start. @@contents @@ifnottex @@node Top @@top @var{title} @@insertcopying @@end ifnottex @group @@menu * First Chapter:: Getting started @dots{} * Second Chapter:: @dots{} @dots{} * Copying:: Your rights and freedoms. @@end menu @end group @group @@node First Chapter @@chapter First Chapter @@cindex first chapter @@cindex chapter, first @dots{} @end group @end example @node Texinfo File Header @section Texinfo File Header @cindex Header for Texinfo files @cindex Texinfo file header Texinfo files start with at least three lines that provide Info and @TeX{} with necessary information. These are the @code{\input texinfo} line, the @code{@@settitle} line, and the @code{@@setfilename} line. Also, if you want to format just part of the Texinfo file, you must write the @code{@@settitle} and @code{@@setfilename} lines between start-of-header and end-of-header lines. The start- and end-of-header lines are optional, but they do no harm, so you might as well always include them. Any command that affects document formatting as a whole makes sense to include in the header. @code{@@synindex} (@pxref{synindex}), for instance, is another command often included in the header. @xref{GNU Sample Texts}, for complete sample texts. Thus, the beginning of a Texinfo file generally looks like this: @example @group \input texinfo @@c -*-texinfo-*- @@c %**start of header @@setfilename sample.info @@settitle Sample Manual 1.0 @@c %**end of header @end group @end example @menu * First Line:: The first line of a Texinfo file. * Start of Header:: Formatting a region requires this. * setfilename:: Tell Info the name of the Info file. * settitle:: Create a title for the printed work. * End of Header:: Formatting a region requires this. @end menu @node First Line @subsection The First Line of a Texinfo File @cindex First line of a Texinfo file @cindex Beginning line of a Texinfo file @cindex Header of a Texinfo file Every Texinfo file that is to be the top-level input to @TeX{} must begin with a line that looks like this: @example \input texinfo @@c -*-texinfo-*- @end example @noindent This line serves two functions: @enumerate @item When the file is processed by @TeX{}, the @samp{\input texinfo} command tells @TeX{} to load the macros needed for processing a Texinfo file. These are in a file called @file{texinfo.tex}, which should have been installed on your system along with either the @TeX{} or Texinfo software. @TeX{} uses the backslash, @samp{\}, to mark the beginning of a command, exactly as Texinfo uses @samp{@@}. The @file{texinfo.tex} file causes the switch from @samp{\} to @samp{@@}; before the switch occurs, @TeX{} requires @samp{\}, which is why it appears at the beginning of the file. @item When the file is edited in GNU Emacs, the @samp{-*-texinfo-*-} mode specification tells Emacs to use Texinfo mode. @end enumerate @node Start of Header @subsection Start of Header @cindex Start of header line A start-of-header line is a Texinfo comment that looks like this: @example @@c %**start of header @end example Write the start-of-header line on the second line of a Texinfo file. Follow the start-of-header line with @code{@@setfilename} and @code{@@settitle} lines and, optionally, with other commands that globally affect the document formatting, such as @code{@@synindex} or @code{@@footnotestyle}; and then by an end-of-header line (@pxref{End of Header}). The start- and end-of-header lines allow you to format only part of a Texinfo file for Info or printing. @xref{texinfo-format commands}. The odd string of characters, @samp{%**}, is to ensure that no other comment is accidentally taken for a start-of-header line. You can change it if you wish by setting the @code{tex-start-of-header} and/or @code{tex-end-of-header} Emacs variables. @xref{Texinfo Mode Printing}. @node setfilename @subsection @code{@@setfilename}: Set the output file name @findex setfilename @cindex Texinfo requires @code{@@setfilename} In order to serve as the primary input file for either @code{makeinfo} or @TeX{}, a Texinfo file must contain a line that looks like this: @example @@setfilename @var{info-file-name} @end example Write the @code{@@setfilename} command at the beginning of a line and follow it on the same line by the Info file name. Do not write anything else on the line; anything on the line after the command is considered part of the file name, including what would otherwise be a comment. @cindex Ignored before @code{@@setfilename} @cindex @samp{\input} source line ignored The Info formatting commands ignore everything written before the @code{@@setfilename} line, which is why the very first line of the file (the @code{\input} line) does not show up in the output. The @code{@@setfilename} line specifies the name of the output file to be generated. This name must be different from the name of the Texinfo file. There are two conventions for choosing the name: you can either remove the extension (such as @samp{.texi}) entirely from the input file name, or, preferably, replace it with the @samp{.info} extension. @cindex Length of file names @cindex File name collision @cindex Info file name, choosing Although an explicit @samp{.info} extension is preferable, some operating systems cannot handle long file names. You can run into a problem even when the file name you specify is itself short enough. This occurs because the Info formatters split a long Info file into short indirect subfiles, and name them by appending @samp{-1}, @samp{-2}, @dots{}, @samp{-10}, @samp{-11}, and so on, to the original file name. (@xref{Tag and Split Files}.) The subfile name @file{texinfo.info-10}, for example, is too long for old systems with a 14-character limit on filenames; so the Info file name for this document is @file{texinfo} rather than @file{texinfo.info}. When @code{makeinfo} is running on operating systems such as MS-DOS which impose severe limits on file names, it may remove some characters from the original file name to leave enough space for the subfile suffix, thus producing files named @file{texin-10}, @file{gcc.i12}, etc. When producing HTML output, @code{makeinfo} will replace any extension with @samp{html}, or add @samp{.html} if the given name has no extension. @pindex texinfo.cnf The @code{@@setfilename} line produces no output when you typeset a manual with @TeX{}, but it is nevertheless essential: it opens the index, cross-reference, and other auxiliary files used by Texinfo, and also reads @file{texinfo.cnf} if that file is present on your system (@pxref{Preparing for TeX,, Preparing for @TeX{}}). @node settitle @subsection @code{@@settitle}: Set the document title @findex settitle In order to be made into a printed manual, a Texinfo file must contain a line that looks like this: @example @@settitle @var{title} @end example Write the @code{@@settitle} command at the beginning of a line and follow it on the same line by the title. This tells @TeX{} the title to use in a header or footer. Do not write anything else on the line; anything on the line after the command is considered part of the title, including what would otherwise be a comment. The @code{@@settitle} command should precede everything that generates actual output. The best place for it is right after the @code{@@setfilename} command (see the previous section). @cindex HTML tag In the HTML file produced by @command{makeinfo}, @var{title} serves as the document @samp{<title>}. It also becomes the default document description in the @samp{<head>} part (@pxref{documentdescription}). The title in the @code{@@settitle} command does not affect the title as it appears on the title page. Thus, the two do not need not match exactly. A practice we recommend is to include the version or edition number of the manual in the @code{@@settitle} title; on the title page, the version number generally appears as a @code{@@subtitle} so it would be omitted from the @code{@@title}. @xref{titlepage}. Conventionally, when @TeX{} formats a Texinfo file for double-sided output, the title is printed in the left-hand (even-numbered) page headings and the current chapter title is printed in the right-hand (odd-numbered) page headings. (@TeX{} learns the title of each chapter from each @code{@@chapter} command.) By default, no page footer is printed. Even if you are printing in a single-sided style, @TeX{} looks for an @code{@@settitle} command line, in case you include the manual title in the heading. @TeX{} prints page headings only for that text that comes after the @code{@@end titlepage} command in the Texinfo file, or that comes after an @code{@@headings} command that turns on headings. (@xref{headings on off, , The @code{@@headings} Command}, for more information.) You may, if you wish, create your own, customized headings and footings. @xref{Headings}, for a detailed discussion of this. @node End of Header @subsection End of Header @cindex End of header line Follow the header lines with an @w{end-of-header} line, which is a Texinfo comment that looks like this: @example @@c %**end of header @end example @xref{Start of Header}. @node Document Permissions @section Document Permissions @cindex Document Permissions @cindex Copying Permissions The copyright notice and copying permissions for a document need to appear in several places in the various Texinfo output formats. Therefore, Texinfo provides a command (@code{@@copying}) to declare this text once, and another command (@code{@@insertcopying}) to insert the text at appropriate points. @menu * copying:: Declare the document's copying permissions. * insertcopying:: Where to insert the permissions. @end menu @node copying @subsection @code{@@copying}: Declare Copying Permissions @findex copying The @code{@@copying} command should be given very early in the document; the recommended location is right after the header material (@pxref{Texinfo File Header}). It conventionally consists of a sentence or two about what the program is, identification of the documentation itself, the legal copyright line, and the copying permissions. Here is a skeletal example: @example @@copying This manual is for @var{program} (version @var{version}, updated @var{date}), which @dots{} Copyright @@copyright@{@} @var{years} @var{copyright-owner}. @@quotation Permission is granted to @dots{} @@end quotation @@end copying @end example The @code{@@quotation} has no legal significance; it's there to improve readability in some contexts. @xref{GNU Sample Texts}, for the full text to be used in GNU manuals. @xref{GNU Free Documentation License}, for the license itself under which GNU and other free manuals are distributed. You need to include the license as an appendix to your document. The text of @code{@@copying} is output as a comment at the beginning of Info, HTML, and XML output files. It is @emph{not} output implicitly in plain text or @TeX{}; it's up to you to use @code{@@insertcopying} to emit the copying information. See the next section for details. @findex copyright The @code{@@copyright@{@}} command generates a @samp{c} inside a circle in output formats that support this (print and HTML). In the other formats (Info and plain text), it generates @samp{(C)}. The copyright notice itself has the following legally defined sequence: @example Copyright @copyright{} @var{years} @var{copyright-owner}. @end example @cindex Copyright word, always in English The word `Copyright' must always be written in English, even if the document is otherwise written in another language. This is due to international law. @cindex Years, in copyright line The list of years should include all years in which a version was completed (even if it was released in a subsequent year). Ranges are not allowed; each year must be written out individually and in full, separated by commas. @cindex Copyright holder for FSF works @cindex Holder of copyright for FSF works @cindex Owner of copyright for FSF works The copyright owner (or owners) is whoever holds legal copyright on the work. In the case of works assigned to the FSF, the owner is `Free Software Foundation, Inc.'. The copyright `line' may actually be split across multiple lines, both in the source document and in the output. This often happens for documents with a long history, having many different years of publication. @xref{Copyright Notices,,,maintain,GNU Maintenance Instructions}, for additional information. @node insertcopying @subsection @code{@@insertcopying}: Include Permissions Text @findex insertcopying @cindex Copying text, including @cindex Permissions text, including @cindex Including permissions text The @code{@@insertcopying} command is simply written on a line by itself, like this: @example @@insertcopying @end example This inserts the text previously defined by @code{@@copying}. To meet legal requirements, it must be used on the copyright page in the printed manual (@pxref{Copyright}). We also strongly recommend using @code{@@insertcopying} in the Top node of your manual (@pxref{The Top Node}), although it is not required legally. Here's why: The @code{@@copying} command itself causes the permissions text to appear in an Info file @emph{before} the first node. The text is also copied into the beginning of each split Info output file, as is legally necessary. This location implies a human reading the manual using Info does @emph{not} see this text (except when using the advanced Info command @kbd{g *}). Therefore, an explicit @code{@@insertcopying} in the Top node makes it apparent to readers that the manual is free. Similarly, the @code{@@copying} text is automatically included at the beginning of each HTML output file, as an HTML comment. Again, this text is not visible (unless the reader views the HTML source). And therefore again, the @code{@@insertcopying} in the Top node is valuable because it makes the copying permissions visible and thus promotes freedom. The permissions text defined by @code{@@copying} also appears automatically at the beginning of the XML output file. @node Titlepage & Copyright Page @section Title and Copyright Pages In hard copy output, the manual's name and author are usually printed on a title page. Copyright information is usually printed on the back of the title page. The title and copyright pages appear in the printed manual, but not in the Info file. Because of this, it is possible to use several slightly obscure @TeX{} typesetting commands that cannot be used in an Info file. In addition, this part of the beginning of a Texinfo file contains the text of the copying permissions that appears in the printed manual. @cindex Title page, for plain text @cindex Copyright page, for plain text You may wish to include titlepage-like information for plain text output. Simply place any such leading material between @code{@@ifplaintext} and @code{@@end ifplaintext}; @command{makeinfo} includes this when writing plain text (@samp{--no-headers}), along with an @code{@@insertcopying}. @menu * titlepage:: Create a title for the printed document. * titlefont center sp:: The @code{@@titlefont}, @code{@@center}, and @code{@@sp} commands. * title subtitle author:: The @code{@@title}, @code{@@subtitle}, and @code{@@author} commands. * Copyright:: How to write the copyright notice and include copying permissions. * end titlepage:: Turn on page headings after the title and copyright pages. * headings on off:: An option for turning headings on and off and double or single sided printing. @end menu @node titlepage @subsection @code{@@titlepage} @cindex Title page @findex titlepage Start the material for the title page and following copyright page with @code{@@titlepage} on a line by itself and end it with @code{@@end titlepage} on a line by itself. The @code{@@end titlepage} command starts a new page and turns on page numbering. (@xref{Headings, , Page Headings}, for details about how to generate page headings.) All the material that you want to appear on unnumbered pages should be put between the @code{@@titlepage} and @code{@@end titlepage} commands. You can force the table of contents to appear there with the @code{@@setcontentsaftertitlepage} command (@pxref{Contents}). @findex page@r{, within @code{@@titlepage}} By using the @code{@@page} command you can force a page break within the region delineated by the @code{@@titlepage} and @code{@@end titlepage} commands and thereby create more than one unnumbered page. This is how the copyright page is produced. (The @code{@@titlepage} command might perhaps have been better named the @code{@@titleandadditionalpages} command, but that would have been rather long!) When you write a manual about a computer program, you should write the version of the program to which the manual applies on the title page. If the manual changes more frequently than the program or is independent of it, you should also include an edition number@footnote{We have found that it is helpful to refer to versions of independent manuals as `editions' and versions of programs as `versions'; otherwise, we find we are liable to confuse each other in conversation by referring to both the documentation and the software with the same words.} for the manual. This helps readers keep track of which manual is for which version of the program. (The `Top' node should also contain this information; see @ref{The Top Node}.) Texinfo provides two main methods for creating a title page. One method uses the @code{@@titlefont}, @code{@@sp}, and @code{@@center} commands to generate a title page in which the words on the page are centered. The second method uses the @code{@@title}, @code{@@subtitle}, and @code{@@author} commands to create a title page with black rules under the title and author lines and the subtitle text set flush to the right hand side of the page. With this method, you do not specify any of the actual formatting of the title page. You specify the text you want, and Texinfo does the formatting. You may use either method, or you may combine them; see the examples in the sections below. @findex shorttitlepage @cindex Bastard title page @cindex Title page, bastard For extremely simple documents, and for the bastard title page in traditional book frontmatter, Texinfo also provides a command @code{@@shorttitlepage} which takes the rest of the line as the title. The argument is typeset on a page by itself and followed by a blank page. @node titlefont center sp @subsection @code{@@titlefont}, @code{@@center}, and @code{@@sp} @findex titlefont @findex center @findex sp @r{(titlepage line spacing)} You can use the @code{@@titlefont}, @code{@@sp}, and @code{@@center} commands to create a title page for a printed document. (This is the first of the two methods for creating a title page in Texinfo.) Use the @code{@@titlefont} command to select a large font suitable for the title itself. You can use @code{@@titlefont} more than once if you have an especially long title. For HTML output, each @code{@@titlefont} command produces an @code{<h1>} heading, but the HTML document @code{<title>} is not affected. For that, you must put an @code{@@settitle} command before the @code{@@titlefont} command (@pxref{settitle}). @need 700 For example: @example @@titlefont@{Texinfo@} @end example Use the @code{@@center} command at the beginning of a line to center the remaining text on that line. Thus, @example @@center @@titlefont@{Texinfo@} @end example @noindent centers the title, which in this example is ``Texinfo'' printed in the title font. Use the @code{@@sp} command to insert vertical space. For example: @example @@sp 2 @end example @noindent This inserts two blank lines on the printed page. (@xref{sp, , @code{@@sp}}, for more information about the @code{@@sp} command.) A template for this method looks like this: @example @group @@titlepage @@sp 10 @@center @@titlefont@{@var{name-of-manual-when-printed}@} @@sp 2 @@center @var{subtitle-if-any} @@sp 2 @@center @var{author} @dots{} @@end titlepage @end group @end example The spacing of the example fits an 8.5 by 11 inch manual. You can in fact use these commands anywhere, not just on a title page, but since they are not logical markup commands, we don't recommend them. @node title subtitle author @subsection @code{@@title}, @code{@@subtitle}, and @code{@@author} @findex title @findex subtitle @findex author You can use the @code{@@title}, @code{@@subtitle}, and @code{@@author} commands to create a title page in which the vertical and horizontal spacing is done for you automatically. This contrasts with the method described in the previous section, in which the @code{@@sp} command is needed to adjust vertical spacing. Write the @code{@@title}, @code{@@subtitle}, or @code{@@author} commands at the beginning of a line followed by the title, subtitle, or author. These commands are only effective in @TeX{} output; it's an error to use them anywhere except within @code{@@titlepage}. The @code{@@title} command produces a line in which the title is set flush to the left-hand side of the page in a larger than normal font. The title is underlined with a black rule. Only a single line is allowed; the @code{@@*} command may not be used to break the title into two lines. To handle very long titles, you may find it profitable to use both @code{@@title} and @code{@@titlefont}; see the final example in this section. The @code{@@subtitle} command sets subtitles in a normal-sized font flush to the right-hand side of the page. The @code{@@author} command sets the names of the author or authors in a middle-sized font flush to the left-hand side of the page on a line near the bottom of the title page. The names are underlined with a black rule that is thinner than the rule that underlines the title. (The black rule only occurs if the @code{@@author} command line is followed by an @code{@@page} command line.) There are two ways to use the @code{@@author} command: you can write the name or names on the remaining part of the line that starts with an @code{@@author} command: @example @@author by Jane Smith and John Doe @end example @noindent or you can write the names one above each other by using two (or more) @code{@@author} commands: @example @group @@author Jane Smith @@author John Doe @end group @end example @noindent (Only the bottom name is underlined with a black rule.) @need 950 A template for this method looks like this: @example @group @@titlepage @@title @var{name-of-manual-when-printed} @@subtitle @var{subtitle-if-any} @@subtitle @var{second-subtitle} @@author @var{author} @@page @dots{} @@end titlepage @end group @end example You may also combine the @code{@@titlefont} method described in the previous section and @code{@@title} method described in this one. This may be useful if you have a very long title. Here is a real-life example: @example @group @@titlepage @@titlefont@{GNU Software@} @@sp 1 @@title for MS-Windows and MS-DOS @@subtitle Edition @@value@{e@} for Release @@value@{cde@} @@author by Daniel Hagerty, Melissa Weisshaus @@author and Eli Zaretskii @end group @end example @noindent (The use of @code{@@value} here is explained in @ref{value Example}. @node Copyright @subsection Copyright Page @cindex Copyright page @cindex Printed permissions @cindex Permissions, printed By international treaty, the copyright notice for a book must be either on the title page or on the back of the title page. When the copyright notice is on the back of the title page, that page is customarily not numbered. Therefore, in Texinfo, the information on the copyright page should be within @code{@@titlepage} and @code{@@end titlepage} commands. @findex vskip @r{@TeX{} vertical skip} @findex filll @r{@TeX{} dimension} Use the @code{@@page} command to cause a page break. To push the copyright notice and the other text on the copyright page towards the bottom of the page, use the following incantantion after @code{@@page}: @example @@vskip 0pt plus 1filll @end example @noindent This is a @TeX{} command that is not supported by the Info formatting commands. The @code{@@vskip} command inserts whitespace. The @samp{0pt plus 1filll} means to put in zero points of mandatory whitespace, and as much optional whitespace as needed to push the following text to the bottom of the page. Note the use of three @samp{l}s in the word @samp{filll}; this is correct. To insert the copyright text itself, write @code{@@insertcopying} next (@pxref{Document Permissions}): @example @@insertcopying @end example Follow the copying text by the publisher, ISBN numbers, cover art credits, and other such information. Here is an example putting all this together: @example @@titlepage @dots{} @@page @@vskip 0pt plus 1filll @@insertcopying Published by @dots{} Cover art by @dots{} @@end titlepage @end example @node end titlepage @subsection Heading Generation @findex end titlepage @cindex Headings, page, begin to appear @cindex Titlepage end starts headings @cindex End titlepage starts headings Like all @code{@@end} commands (@pxref{Quotations and Examples}), the @code{@@end titlepage} command must be written at the beginning of a line by itself, with only one space between the @code{@@end} and the @code{titlepage}. It not only marks the end of the title and copyright pages, but also causes @TeX{} to start generating page headings and page numbers. To repeat what is said elsewhere, Texinfo has two standard page heading formats, one for documents which are printed on one side of each sheet of paper (single-sided printing), and the other for documents which are printed on both sides of each sheet (double-sided printing). You can specify these formats in different ways: @itemize @bullet @item The conventional way is to write an @code{@@setchapternewpage} command before the title page commands, and then have the @code{@@end titlepage} command start generating page headings in the manner desired. (@xref{setchapternewpage}.) @item Alternatively, you can use the @code{@@headings} command to prevent page headings from being generated or to start them for either single or double-sided printing. (Write an @code{@@headings} command immediately after the @code{@@end titlepage} command. @xref{headings on off, , The @code{@@headings} Command}, for more information.)@refill @item Or, you may specify your own page heading and footing format. @xref{Headings, , Page Headings}, for detailed information about page headings and footings. @end itemize Most documents are formatted with the standard single-sided or double-sided format, using @code{@@setchapternewpage odd} for double-sided printing and no @code{@@setchapternewpage} command for single-sided printing. @node headings on off @subsection The @code{@@headings} Command @findex headings The @code{@@headings} command is rarely used. It specifies what kind of page headings and footings to print on each page. Usually, this is controlled by the @code{@@setchapternewpage} command. You need the @code{@@headings} command only if the @code{@@setchapternewpage} command does not do what you want, or if you want to turn off pre-defined page headings prior to defining your own. Write an @code{@@headings} command immediately after the @code{@@end titlepage} command.@refill You can use @code{@@headings} as follows:@refill @table @code @item @@headings off Turn off printing of page headings.@refill @item @@headings single Turn on page headings appropriate for single-sided printing. @refill @item @@headings double @itemx @@headings on Turn on page headings appropriate for double-sided printing. The two commands, @code{@@headings on} and @code{@@headings double}, are synonymous.@refill @item @@headings singleafter @itemx @@headings doubleafter Turn on @code{single} or @code{double} headings, respectively, after the current page is output. @item @@headings on Turn on page headings: @code{single} if @samp{@@setchapternewpage on}, @code{double} otherwise. @end table For example, suppose you write @code{@@setchapternewpage off} before the @code{@@titlepage} command to tell @TeX{} to start a new chapter on the same page as the end of the last chapter. This command also causes @TeX{} to typeset page headers for single-sided printing. To cause @TeX{} to typeset for double sided printing, write @code{@@headings double} after the @code{@@end titlepage} command. You can stop @TeX{} from generating any page headings at all by writing @code{@@headings off} on a line of its own immediately after the line containing the @code{@@end titlepage} command, like this:@refill @example @@end titlepage @@headings off @end example @noindent The @code{@@headings off} command overrides the @code{@@end titlepage} command, which would otherwise cause @TeX{} to print page headings.@refill You can also specify your own style of page heading and footing. @xref{Headings, , Page Headings}, for more information.@refill @node Contents @section Generating a Table of Contents @cindex Table of contents @cindex Contents, Table of @cindex Short table of contents @findex contents @findex summarycontents @findex shortcontents The @code{@@chapter}, @code{@@section}, and other structuring commands (@pxref{Structuring}) supply the information to make up a table of contents, but they do not cause an actual table to appear in the manual. To do this, you must use the @code{@@contents} and/or @code{@@summarycontents} command(s). @table @code @item @@contents Generates a table of contents in a printed manual, including all chapters, sections, subsections, etc., as well as appendices and unnumbered chapters. Headings generated by @code{@@majorheading}, @code{@@chapheading}, and the other @code{@@@dots{}heading} commands do not appear in the table of contents (@pxref{Structuring Command Types}). @item @@shortcontents @itemx @@summarycontents (@code{@@summarycontents} is a synonym for @code{@@shortcontents}.) Generates a short or summary table of contents that lists only the chapters, appendices, and unnumbered chapters. Sections, subsections and subsubsections are omitted. Only a long manual needs a short table of contents in addition to the full table of contents. @end table Both contents commands should be written on a line by themselves, and are best placed near the beginning of the file, after the @code{@@end titlepage} (@pxref{titlepage}). The contents commands automatically generate a chapter-like heading at the top of the first table of contents page, so don't include any sectioning command such as @code{@@unnumbered} before them. Since an Info file uses menus instead of tables of contents, the Info formatting commands ignore the contents commands. But the contents are included in plain text output (generated by @code{makeinfo --no-headers}), unless @code{makeinfo} is writing its output to standard output. When @code{makeinfo} writes a short table of contents while producing html output, the links in the short table of contents point to corresponding entries in the full table of contents rather than the text of the document. The links in the full table of contents point to the main text of the document. In the past, the contents commands were sometimes placed at the end of the file, after any indices and just before the @code{@@bye}, but we no longer recommend this. @findex setcontentsaftertitlepage @findex setshortcontentsaftertitlepage @cindex Contents, after title page @cindex Table of contents, after title page However, since many existing Texinfo documents still do have the @code{@@contents} at the end of the manual, if you are a user printing a manual, you may wish to force the contents to be printed after the title page. You can do this by specifying @code{@@setcontentsaftertitlepage} and/or @code{@@setshortcontentsaftertitlepage}. The first prints only the main contents after the @code{@@end titlepage}; the second prints both the short contents and the main contents. In either case, any subsequent @code{@@contents} or @code{@@shortcontents} is ignored (unless, erroneously, no @code{@@end titlepage} is ever encountered). You need to include the @code{@@set@dots{}contentsaftertitlepage} commands early in the document (just after @code{@@setfilename}, for example). We recommend using @command{texi2dvi} (@pxref{Format with texi2dvi}) to specify this without altering the source file at all. For example: @example texi2dvi --texinfo=@@setcontentsaftertitlepage foo.texi @end example @node The Top Node @section The `Top' Node and Master Menu @cindex Top node @cindex Node, `Top' The `Top' node is the node in which a reader enters an Info manual. As such, it should begin with the @code{@@insertcopying} command (@pxref{Document Permissions}) to provide a brief description of the manual (including the version number) and copying permissions, and end with a master menu for the whole manual. Of course you should include any other general information you feel a reader would find helpful. @findex top It is also conventional to write an @code{@@top} sectioning command line containing the title of the document immediately after the @code{@@node Top} line (@pxref{makeinfo top command, , The @code{@@top} Sectioning Command}). The contents of the `Top' node should appear only in the online output; none of it should appear in printed output, so enclose it between @code{@@ifnottex} and @code{@@end ifnottex} commands. (@TeX{} does not print either an @code{@@node} line or a menu; they appear only in Info; strictly speaking, you are not required to enclose these parts between @code{@@ifnottex} and @code{@@end ifnottext}, but it is simplest to do so. @xref{Conditionals, , Conditionally Visible Text}.) @menu * Top Node Example:: * Master Menu Parts:: @end menu @node Top Node Example @subsection Top Node Example @cindex Top node example Here is an example of a Top node. @example @group @@ifnottex @@node Top @@top Sample Title @@insertcopying @end group Additional general information. @group @@menu * First Chapter:: * Second Chapter:: @dots{} * Index:: @end group @@end menu @end example @node Master Menu Parts @subsection Parts of a Master Menu @cindex Master menu @cindex Menu, master @cindex Parts of a master menu A @dfn{master menu} is a detailed main menu listing all the nodes in a file. A master menu is enclosed in @code{@@menu} and @code{@@end menu} commands and does not appear in the printed document. Generally, a master menu is divided into parts. @itemize @bullet @item The first part contains the major nodes in the Texinfo file: the nodes for the chapters, chapter-like sections, and the appendices. @item The second part contains nodes for the indices. @item The third and subsequent parts contain a listing of the other, lower level nodes, often ordered by chapter. This way, rather than go through an intermediary menu, an inquirer can go directly to a particular node when searching for specific information. These menu items are not required; add them if you think they are a convenience. If you do use them, put @code{@@detailmenu} before the first one, and @code{@@end detailmenu} after the last; otherwise, @code{makeinfo} will get confused. @end itemize Each section in the menu can be introduced by a descriptive line. So long as the line does not begin with an asterisk, it will not be treated as a menu entry. (@xref{Writing a Menu}, for more information.) For example, the master menu for this manual looks like the following (but has many more entries): @example @group @@menu * Copying Conditions:: Your rights. * Overview:: Texinfo in brief. @dots{} @end group @group * Command and Variable Index:: * Concept Index:: @end group @group @@detailmenu --- The Detailed Node Listing --- Overview of Texinfo * Reporting Bugs:: @dots{} @dots{} @end group @group Beginning a Texinfo File * Sample Beginning:: @dots{} @dots{} @@end detailmenu @@end menu @end group @end example @node Global Document Commands @section Global Document Commands @cindex Global Document Commands Besides the basic commands mentioned in the previous sections, here are additional commands which affect the document as a whole. They are generally all given before the Top node, if they are given at all. @menu * documentdescription:: Document summary for the HTML output. * setchapternewpage:: Start chapters on right-hand pages. * paragraphindent:: Specify paragraph indentation. * firstparagraphindent:: Suppress indentation of the first paragraph. * exampleindent:: Specify environment indentation. @end menu @node documentdescription @subsection @code{@@documentdescription}: Summary Text @cindex Document description @cindex Description of document @cindex Summary of document @cindex Abstract of document @cindex <meta> HTML tag, and document description @findex documentdescription When producing HTML output for a document, @command{makeinfo} writes a @samp{<meta>} element in the @samp{<head>} to give some idea of the content of the document. By default, this @dfn{description} is the title of the document, taken from the @code{@@settitle} command (@pxref{settitle}). To change this, use the @code{@@documentdescription} environment, as in: @example @@documentdescription descriptive text. @@end documentdescription @end example @noindent This will produce the following output in the @samp{<head>} of the HTML: @example <meta name=description content="descriptive text."> @end example @code{@@documentdescription} must be specified before the first node of the document. @node setchapternewpage @subsection @code{@@setchapternewpage}: @cindex Starting chapters @cindex Pages, starting odd @findex setchapternewpage In an officially bound book, text is usually printed on both sides of the paper, chapters start on right-hand pages, and right-hand pages have odd numbers. But in short reports, text often is printed only on one side of the paper. Also in short reports, chapters sometimes do not start on new pages, but are printed on the same page as the end of the preceding chapter, after a small amount of vertical whitespace. You can use the @code{@@setchapternewpage} command with various arguments to specify how @TeX{} should start chapters and whether it should format headers for printing on one or both sides of the paper (single-sided or double-sided printing). Write the @code{@@setchapternewpage} command at the beginning of a line followed by its argument. For example, you would write the following to cause each chapter to start on a fresh odd-numbered page: @example @@setchapternewpage odd @end example You can specify one of three alternatives with the @code{@@setchapternewpage} command: @table @asis @item @code{@@setchapternewpage off} Cause @TeX{} to typeset a new chapter on the same page as the last chapter, after skipping some vertical whitespace. Also, cause @TeX{} to format page headers for single-sided printing. @item @code{@@setchapternewpage on} Cause @TeX{} to start new chapters on new pages and to format page headers for single-sided printing. This is the form most often used for short reports or personal printing. This is the default. @item @code{@@setchapternewpage odd} Cause @TeX{} to start new chapters on new, odd-numbered pages (right-handed pages) and to typeset for double-sided printing. This is the form most often used for books and manuals. @end table Texinfo does not have an @code{@@setchapternewpage even} command, because there is no printing tradition of starting chapters or books on an even-numbered page. If you don't like the default headers that @code{@@setchapternewpage} sets, you can explicit control them with the @code{@@headings} command. @xref{headings on off, , The @code{@@headings} Command}. At the beginning of a manual or book, pages are not numbered---for example, the title and copyright pages of a book are not numbered. By convention, table of contents and frontmatter pages are numbered with roman numerals and not in sequence with the rest of the document. Since an Info file does not have pages, the @code{@@setchapternewpage} command has no effect on it. We recommend not including any @code{@@setchapternewpage} command in your manual sources at all, since the desired output is not intrinsic to the document. For a particular hard copy run, if you don't want the default option (no blank pages, same headers on all pages) use the @option{--texinfo} option to @command{texi2dvi} to specify the output you want. @node paragraphindent @subsection @code{@@paragraphindent}: Paragraph Indenting @cindex Indenting paragraphs, control of @cindex Paragraph indentation control @findex paragraphindent The Texinfo processors may insert whitespace at the beginning of the first line of each paragraph, thereby indenting that paragraph. You can use the @code{@@paragraphindent} command to specify this indentation. Write an @code{@@paragraphindent} command at the beginning of a line followed by either @samp{asis} or a number: @example @@paragraphindent @var{indent} @end example The indentation is according to the value of @var{indent}: @table @asis @item @code{asis} Do not change the existing indentation (not implemented in @TeX{}). @item @code{none} @itemx 0 Omit all indentation. @item @var{n} Indent by @var{n} space characters in Info output, by @var{n} ems in @TeX{}. @end table The default value of @var{indent} is 3. @code{@@paragraphindent} is ignored for HTML output. It is best to write the @code{@@paragraphindent} command before the end-of-header line at the beginning of a Texinfo file, so the region formatting commands indent paragraphs as specified. @xref{Start of Header}. A peculiarity of the @code{texinfo-format-buffer} and @code{texinfo-format-region} commands is that they do not indent (nor fill) paragraphs that contain @code{@@w} or @code{@@*} commands. @node firstparagraphindent @subsection @code{@@firstparagraphindent}: Indenting After Headings @cindex First paragraph, suppressing indentation of @cindex Suppressing first paragraph indentation @cindex Preventing first paragraph indentation @cindex Indenting, suppressing of first paragraph @cindex Headings, indentation after @findex firstparagraphindent As you can see in the present manual, the first paragraph in any section is not indented by default. Typographically, indentation is a paragraph separator, which means that it is unnecessary when a new section begins. This indentation is controlled with the @code{@@firstparagraphindent} command: @example @@firstparagraphindent @var{word} @end example The first paragraph after a heading is indented according to the value of @var{word}: @table @asis @item @code{none} Prevents the first paragraph from being indented (default). This option is ignored by @command{makeinfo} if @code{@@paragraphindent asis} is in effect. @item @code{insert} Include normal paragraph indentation. This respects the paragraph indentation set by a @code{@@paragraphindent} command (@pxref{paragraphindent}). @end table For HTML and XML output, the @code{@@firstparagraphindent} setting is ignored. It is best to write the @code{@@paragraphindent} command before the end-of-header line at the beginning of a Texinfo file, so the region formatting commands indent paragraphs as specified. @xref{Start of Header}. @node exampleindent @subsection @code{@@exampleindent}: Environment Indenting @cindex Indenting environments @cindex Environment indentation @cindex Example indentation @findex exampleindent The Texinfo processors indent each line of @code{@@example} and similar environments. You can use the @code{@@exampleindent} command to specify this indentation. Write an @code{@@exampleindent} command at the beginning of a line followed by either @samp{asis} or a number: @example @@exampleindent @var{indent} @end example @code{@@exampleindent} is ignored for HTML output. Otherwise, the indentation is according to the value of @var{indent}: @table @asis @item @code{asis} Do not change the existing indentation (not implemented in @TeX{}). @item 0 Omit all indentation. @item @var{n} Indent environments by @var{n} space characters in Info output, by @var{n} ems in @TeX{}. @end table The default value of @var{indent} is 5 spaces in Info, and 0.4@dmn{in} in @TeX{}, which is somewhat less. (The reduction is to help @TeX{} fit more characters onto physical lines.) It is best to write the @code{@@exampleindent} command before the end-of-header line at the beginning of a Texinfo file, so the region formatting commands indent paragraphs as specified. @xref{Start of Header}. @node Software Copying Permissions @section Software Copying Permissions @cindex Software copying permissions @cindex Copying software @cindex Distribution @cindex License agreement If the Texinfo file has a section containing the ``General Public License'' and the distribution information and a warranty disclaimer for the software that is documented, we recommend placing this right after the `Top' node. The General Public License is very important to Project GNU software. It ensures that you and others will continue to have a right to use and share the software. The copying and distribution information and the disclaimer are followed by an introduction or else by the first chapter of the manual. @cindex Introduction, as part of file Although an introduction is not a required part of a Texinfo file, it is very helpful. Ideally, it should state clearly and concisely what the file is about and who would be interested in reading it. In general, an introduction would follow the licensing and distribution information, although sometimes people put it earlier in the document. @node Ending a File @chapter Ending a Texinfo File @cindex Ending a Texinfo file @cindex Texinfo file ending @cindex File ending @findex bye The end of a Texinfo file should include commands to create indices, and the @code{@@bye} command to mark the last line to be processed. For example: @example @@node Index @@unnumbered Index @@printindex cp @@bye @end example @menu * Printing Indices & Menus:: How to print an index in hardcopy and generate index menus in Info. * File End:: How to mark the end of a file. @end menu @node Printing Indices & Menus @section Printing Indices and Menus @cindex Printing an index @cindex Indices, printing and menus @cindex Generating menus with indices @cindex Menus generated with indices To print an index means to include it as part of a manual or Info file. This does not happen automatically just because you use @code{@@cindex} or other index-entry generating commands in the Texinfo file; those just cause the raw data for the index to be accumulated. To generate an index, you must include the @code{@@printindex} command at the place in the document where you want the index to appear. Also, as part of the process of creating a printed manual, you must run a program called @code{texindex} (@pxref{Hardcopy}) to sort the raw data to produce a sorted index file. The sorted index file is what is actually used to print the index. Texinfo offers six separate types of predefined index, which suffice in most cases. @xref{Indices}, for information on this, as well defining your own new indices, combining indices, and, most importantly advice on writing the actual index entries. This section focuses on printing indices, which is done with the @code{@@printindex} command. @findex printindex @code{@@printindex} takes one argument, a two-letter index abbreviation. It reads the corresponding sorted index file (for printed output), and formats it appropriately into an index. The @code{@@printindex} command does not generate a chapter heading for the index, since different manuals have different needs. Consequently, you should precede the @code{@@printindex} command with a suitable section or chapter command (usually @code{@@appendix} or @code{@@unnumbered}) to supply the chapter heading and put the index into the table of contents. Precede the chapter heading with an @code{@@node} line as usual. For example: @smallexample @group @@node Variable Index @@unnumbered Variable Index @@printindex vr @end group @group @@node Concept Index @@unnumbered Concept Index @@printindex cp @end group @end smallexample If you have more than one index, we recommend placing the concept index last. @itemize @item In printed output, @code{@@printindex} produces a traditional two-column index, with dot leaders between the index terms and page numbers. @item In Info output, @code{@@printindex} produces a special menu containing the line number of the entry, relative to the start of the node. Info readers can use this to go to the exact line of an entry, not just the containing node. (Older Info readers will just go to the node.) Here's an example: @smallexample * First index entry: Top. (line 7) @end smallexample @noindent The actual number of spaces is variable, to right-justify the line number; it's been reduced here to make the line fit in the printed manual. @item In plain text output, @code{@@printindex} produces the same menu, but the line numbers are relative to the start of the file, since that's more convenient for that format. @item In HTML and Docbook output, @code{@@printindex} produces links to the index entries. @item In XML output, it simply records the index to be printed. @end itemize It's not possible to generate an index when writing to standard output; @command{makeinfo} generates a warning in this case. @node File End @section @code{@@bye} File Ending @findex bye An @code{@@bye} command terminates Texinfo processing. None of the formatters read anything following @code{@@bye}. The @code{@@bye} command should be on a line by itself. If you wish, you may follow the @code{@@bye} line with notes. These notes will not be formatted and will not appear in either Info or a printed manual; it is as if text after @code{@@bye} were within @code{@@ignore} @dots{} @code{@@end ignore}. Also, you may follow the @code{@@bye} line with a local variables list for Emacs. @xref{Compile-Command, , Using Local Variables and the Compile Command}, for more information. @node Structuring @chapter Chapter Structuring @cindex Chapter structuring @cindex Structuring of chapters The @dfn{chapter structuring} commands divide a document into a hierarchy of chapters, sections, subsections, and subsubsections. These commands generate large headings; they also provide information for the table of contents of a printed manual (@pxref{Contents, , Generating a Table of Contents}).@refill The chapter structuring commands do not create an Info node structure, so normally you should put an @code{@@node} command immediately before each chapter structuring command (@pxref{Nodes}). The only time you are likely to use the chapter structuring commands without using the node structuring commands is if you are writing a document that contains no cross references and will never be transformed into Info format.@refill It is unlikely that you will ever write a Texinfo file that is intended only as an Info file and not as a printable document. If you do, you might still use chapter structuring commands to create a heading at the top of each node---but you don't need to.@refill @menu * Tree Structuring:: A manual is like an upside down tree @dots{} * Structuring Command Types:: How to divide a manual into parts. * makeinfo top:: The @code{@@top} command, part of the `Top' node. * chapter:: * unnumbered & appendix:: * majorheading & chapheading:: * section:: * unnumberedsec appendixsec heading:: * subsection:: * unnumberedsubsec appendixsubsec subheading:: * subsubsection:: Commands for the lowest level sections. * Raise/lower sections:: How to change commands' hierarchical level. @end menu @node Tree Structuring @section Tree Structure of Sections @cindex Tree structuring A Texinfo file is usually structured like a book with chapters, sections, subsections, and the like. This structure can be visualized as a tree (or rather as an upside-down tree) with the root at the top and the levels corresponding to chapters, sections, subsection, and subsubsections.@refill Here is a diagram that shows a Texinfo file with three chapters, each of which has two sections.@refill @example @group Top | ------------------------------------- | | | Chapter 1 Chapter 2 Chapter 3 | | | -------- -------- -------- | | | | | | Section Section Section Section Section Section 1.1 1.2 2.1 2.2 3.1 3.2 @end group @end example In a Texinfo file that has this structure, the beginning of Chapter 2 looks like this:@refill @example @group @@node Chapter 2, Chapter 3, Chapter 1, top @@chapter Chapter 2 @end group @end example The chapter structuring commands are described in the sections that follow; the @code{@@node} and @code{@@menu} commands are described in following chapters. (@xref{Nodes}, and see @ref{Menus}.)@refill @node Structuring Command Types @section Structuring Command Types The chapter structuring commands fall into four groups or series, each of which contains structuring commands corresponding to the hierarchical levels of chapters, sections, subsections, and subsubsections.@refill The four groups are the @code{@@chapter} series, the @code{@@unnumbered} series, the @code{@@appendix} series, and the @code{@@heading} series.@refill Each command produces titles that have a different appearance on the printed page or Info file; only some of the commands produce titles that are listed in the table of contents of a printed book or manual.@refill @itemize @bullet @item The @code{@@chapter} and @code{@@appendix} series of commands produce numbered or lettered entries both in the body of a printed work and in its table of contents.@refill @item The @code{@@unnumbered} series of commands produce unnumbered entries both in the body of a printed work and in its table of contents. The @code{@@top} command, which has a special use, is a member of this series (@pxref{makeinfo top, , @code{@@top}}). An @code{@@unnumbered} section should be associated with a node and be a normal part of the document structure. @item The @code{@@heading} series of commands produce simple unnumbered headings that do not appear in a table of contents, are not associated with nodes, and cannot be cross-referenced. The heading commands never start a new page. @item The @code{@@majorheading} command is similar to @code{@@chapheading}, except that it generates a larger vertical whitespace before the heading. @item When an @code{@@setchapternewpage} command says to do so, the @code{@@chapter}, @code{@@unnumbered}, and @code{@@appendix} commands start new pages in the printed manual; the @code{@@heading} commands do not.@refill @end itemize Here are the four groups of chapter structuring commands: @tex {\globaldefs = 1 \smallfonts} @end tex @multitable @columnfractions .19 .30 .29 .22 @item @tab @tab @tab No new page @item @i{Numbered} @tab @i{Unnumbered} @tab @i{Lettered/numbered} @tab @i{Unnumbered} @item In contents @tab In contents @tab In contents @tab Not in contents @item @tab @code{@@top} @tab @tab @code{@@majorheading} @item @code{@@chapter} @tab @code{@@unnumbered} @tab @code{@@appendix} @tab @code{@@chapheading} @item @code{@@section} @tab @code{@@unnumberedsec} @tab @code{@@appendixsec} @tab @code{@@heading} @item @code{@@subsection} @tab @code{@@unnumberedsubsec} @tab @code{@@appendixsubsec} @tab @code{@@subheading} @item @code{@@subsubsection} @tab @code{@@unnumberedsubsubsec} @tab @code{@@appendixsubsubsec} @tab @code{@@subsubheading} @end multitable @tex {\globaldefs = 1 \textfonts} @end tex @node makeinfo top @section @code{@@top} The @code{@@top} command is a special sectioning command that you use only after an @samp{@@node Top} line at the beginning of a Texinfo file. The @code{@@top} command tells the @code{makeinfo} formatter which node is the `Top' node, so it can use it as the root of the node tree if your manual uses implicit node pointers. It has the same typesetting effect as @code{@@unnumbered} (@pxref{unnumbered & appendix, , @code{@@unnumbered} and @code{@@appendix}}). For detailed information, see @ref{makeinfo top command, , The @code{@@top} Command}. The @code{@@top} node and its menu (if any) is conventionally wrapped in an @code{@@ifnottex} conditional so that it will appear only in Info and HTML output, not @TeX{}. @node chapter @comment node-name, next, previous, up @section @code{@@chapter} @findex chapter @code{@@chapter} identifies a chapter in the document. Write the command at the beginning of a line and follow it on the same line by the title of the chapter.@refill For example, this chapter in this manual is entitled ``Chapter Structuring''; the @code{@@chapter} line looks like this:@refill @example @@chapter Chapter Structuring @end example In @TeX{}, the @code{@@chapter} command creates a chapter in the document, specifying the chapter title. The chapter is numbered automatically.@refill In Info, the @code{@@chapter} command causes the title to appear on a line by itself, with a line of asterisks inserted underneath. Thus, in Info, the above example produces the following output:@refill @example Chapter Structuring ******************* @end example @findex centerchap Texinfo also provides a command @code{@@centerchap}, which is analogous to @code{@@unnumbered}, but centers its argument in the printed output. This kind of stylistic choice is not usually offered by Texinfo. @c but the Hacker's Dictionary wanted it ... @node unnumbered & appendix @section @code{@@unnumbered} and @code{@@appendix} @findex unnumbered @findex appendix Use the @code{@@unnumbered} command to create a chapter that appears in a printed manual without chapter numbers of any kind. Use the @code{@@appendix} command to create an appendix in a printed manual that is labelled by letter instead of by number.@refill For Info file output, the @code{@@unnumbered} and @code{@@appendix} commands are equivalent to @code{@@chapter}: the title is printed on a line by itself with a line of asterisks underneath. (@xref{chapter, , @code{@@chapter}}.)@refill To create an appendix or an unnumbered chapter, write an @code{@@appendix} or @code{@@unnumbered} command at the beginning of a line and follow it on the same line by the title, as you would if you were creating a chapter.@refill @node majorheading & chapheading @section @code{@@majorheading}, @code{@@chapheading} @findex majorheading @findex chapheading The @code{@@majorheading} and @code{@@chapheading} commands put chapter-like headings in the body of a document.@refill However, neither command causes @TeX{} to produce a numbered heading or an entry in the table of contents; and neither command causes @TeX{} to start a new page in a printed manual.@refill In @TeX{}, an @code{@@majorheading} command generates a larger vertical whitespace before the heading than an @code{@@chapheading} command but is otherwise the same. In Info, the @code{@@majorheading} and @code{@@chapheading} commands are equivalent to @code{@@chapter}: the title is printed on a line by itself with a line of asterisks underneath. (@xref{chapter, , @code{@@chapter}}.)@refill @node section @comment node-name, next, previous, up @section @code{@@section} @findex section In a printed manual, an @code{@@section} command identifies a numbered section within a chapter. The section title appears in the table of contents. In Info, an @code{@@section} command provides a title for a segment of text, underlined with @samp{=}.@refill This section is headed with an @code{@@section} command and looks like this in the Texinfo file:@refill @example @@section @@code@{@@@@section@} @end example To create a section, write the @code{@@section} command at the beginning of a line and follow it on the same line by the section title.@refill Thus, @example @@section This is a section @end example @noindent produces @example @group This is a section ================= @end group @end example @noindent in Info. @node unnumberedsec appendixsec heading @comment node-name, next, previous, up @section @code{@@unnumberedsec}, @code{@@appendixsec}, @code{@@heading} @findex unnumberedsec @findex appendixsec @findex heading The @code{@@unnumberedsec}, @code{@@appendixsec}, and @code{@@heading} commands are, respectively, the unnumbered, appendix-like, and heading-like equivalents of the @code{@@section} command. (@xref{section, , @code{@@section}}.)@refill @table @code @item @@unnumberedsec The @code{@@unnumberedsec} command may be used within an unnumbered chapter or within a regular chapter or appendix to provide an unnumbered section.@refill @item @@appendixsec @itemx @@appendixsection @code{@@appendixsection} is a longer spelling of the @code{@@appendixsec} command; the two are synonymous.@refill @findex appendixsection Conventionally, the @code{@@appendixsec} or @code{@@appendixsection} command is used only within appendices.@refill @item @@heading You may use the @code{@@heading} command anywhere you wish for a section-style heading that will not appear in the table of contents.@refill @end table @node subsection @comment node-name, next, previous, up @section The @code{@@subsection} Command @findex subsection Subsections are to sections as sections are to chapters. (@xref{section, , @code{@@section}}.) In Info, subsection titles are underlined with @samp{-}. For example,@refill @example @@subsection This is a subsection @end example @noindent produces @example @group This is a subsection -------------------- @end group @end example In a printed manual, subsections are listed in the table of contents and are numbered three levels deep.@refill @node unnumberedsubsec appendixsubsec subheading @comment node-name, next, previous, up @section The @code{@@subsection}-like Commands @cindex Subsection-like commands @findex unnumberedsubsec @findex appendixsubsec @findex subheading The @code{@@unnumberedsubsec}, @code{@@appendixsubsec}, and @code{@@subheading} commands are, respectively, the unnumbered, appendix-like, and heading-like equivalents of the @code{@@subsection} command. (@xref{subsection, , @code{@@subsection}}.)@refill In Info, the @code{@@subsection}-like commands generate a title underlined with hyphens. In a printed manual, an @code{@@subheading} command produces a heading like that of a subsection except that it is not numbered and does not appear in the table of contents. Similarly, an @code{@@unnumberedsubsec} command produces an unnumbered heading like that of a subsection and an @code{@@appendixsubsec} command produces a subsection-like heading labelled with a letter and numbers; both of these commands produce headings that appear in the table of contents.@refill @node subsubsection @section The `subsub' Commands @cindex Subsub commands @findex subsubsection @findex unnumberedsubsubsec @findex appendixsubsubsec @findex subsubheading The fourth and lowest level sectioning commands in Texinfo are the `subsub' commands. They are:@refill @table @code @item @@subsubsection Subsubsections are to subsections as subsections are to sections. (@xref{subsection, , @code{@@subsection}}.) In a printed manual, subsubsection titles appear in the table of contents and are numbered four levels deep.@refill @item @@unnumberedsubsubsec Unnumbered subsubsection titles appear in the table of contents of a printed manual, but lack numbers. Otherwise, unnumbered subsubsections are the same as subsubsections. In Info, unnumbered subsubsections look exactly like ordinary subsubsections.@refill @item @@appendixsubsubsec Conventionally, appendix commands are used only for appendices and are lettered and numbered appropriately in a printed manual. They also appear in the table of contents. In Info, appendix subsubsections look exactly like ordinary subsubsections.@refill @item @@subsubheading The @code{@@subsubheading} command may be used anywhere that you need a small heading that will not appear in the table of contents. In Info, subsubheadings look exactly like ordinary subsubsection headings.@refill @end table In Info, `subsub' titles are underlined with periods. For example,@refill @example @@subsubsection This is a subsubsection @end example @noindent produces @example @group This is a subsubsection ....................... @end group @end example @node Raise/lower sections @section @code{@@raisesections} and @code{@@lowersections} @findex raisesections @findex lowersections @cindex Raising and lowering sections @cindex Lowering and raising sections @cindex Sections, raising and lowering The @code{@@raisesections} and @code{@@lowersections} commands implicitly raise and lower the hierarchical level of following chapters, sections and the other sectioning commands. That is, the @code{@@raisesections} command changes sections to chapters, subsections to sections, and so on. Conversely, the @code{@@lowersections} command changes chapters to sections, sections to subsections, and so on. Thus, an @code{@@lowersections} command cancels an @code{@@raisesections} command, and vice versa. @cindex Include files, and section levels You can use @code{@@lowersections} to include text written as an outer or standalone Texinfo file in another Texinfo file as an inner, included file. Typical usage looks like this: @example @@lowersections @@include somefile.texi @@raisesections @end example @noindent (Without the @code{@@raisesections}, all the subsequent sections in the document would be lowered.) If the included file being lowered has a @code{@@top} node, you'll need to conditionalize its inclusion with a flag (@pxref{set value}). Another difficulty can arise with documents that use the (recommended) feature of @command{makeinfo} for implicitly determining node pointers. Since @command{makeinfo} must assume a hierarchically organized document to determine the pointers, you cannot just arbitrarily sprinkle @code{@@raisesections} and @code{@@lowersections} commands in the document. The final result has to have menus that take the raising and lowering into account. Therefore, as a practical matter, you generally only want to raise or lower large chunks, usually in external files as shown above. Repeated use of the commands continue to raise or lower the hierarchical level a step at a time. An attempt to raise above `chapter' reproduces chapter commands; an attempt to lower below `subsubsection' reproduces subsubsection commands. Also, lowered subsubsections and raised chapters will not work with @command{makeinfo}'s feature of implicitly determining node pointers, since the menu structure won't be correct. Write each @code{@@raisesections} and @code{@@lowersections} command on a line of its own. @node Nodes @chapter Nodes @dfn{Nodes} are the primary segments of a Texinfo file. They do not in and of themselves impose a hierarchical or any other kind of structure on a file. Nodes contain @dfn{node pointers} that name other nodes, and can contain @dfn{menus} which are lists of nodes. In Info, the movement commands can carry you to a pointed-to node or to a node listed in a menu. Node pointers and menus provide structure for Info files just as chapters, sections, subsections, and the like, provide structure for printed books. Because node names are used in cross-references, it is not desirable to casually change them. Such name changes invalidate references from other manuals, from mail archives, and so on. @menu * Two Paths:: Different commands to structure Info output and printed output. * Node Menu Illustration:: A diagram, and sample nodes and menus. * node:: Creating nodes, in detail. * makeinfo Pointer Creation:: Letting makeinfo determine node pointers. * anchor:: Defining arbitrary cross-reference targets. @end menu @node Two Paths @section Two Paths The node and menu commands and the chapter structuring commands are technically independent of each other: @itemize @bullet @item In Info, node and menu commands provide structure. The chapter structuring commands generate headings with different kinds of underlining---asterisks for chapters, hyphens for sections, and so on; they do nothing else.@refill @item In @TeX{}, the chapter structuring commands generate chapter and section numbers and tables of contents. The node and menu commands provide information for cross references; they do nothing else.@refill @end itemize You can use node pointers and menus to structure an Info file any way you want; and you can write a Texinfo file so that its Info output has a different structure than its printed output. However, virtually all Texinfo files are written such that the structure for the Info output corresponds to the structure for the printed output. It is neither convenient nor understandable to the reader to do otherwise.@refill Generally, printed output is structured in a tree-like hierarchy in which the chapters are the major limbs from which the sections branch out. Similarly, node pointers and menus are organized to create a matching structure in the Info output.@refill @node Node Menu Illustration @section Node and Menu Illustration Here is a copy of the diagram shown earlier that illustrates a Texinfo file with three chapters, each of which contains two sections.@refill The ``root'' is at the top of the diagram and the ``leaves'' are at the bottom. This is how such a diagram is drawn conventionally; it illustrates an upside-down tree. For this reason, the root node is called the `Top' node, and `Up' node pointers carry you closer to the root.@refill @example @group Top | ------------------------------------- | | | Chapter 1 Chapter 2 Chapter 3 | | | -------- -------- -------- | | | | | | Section Section Section Section Section Section 1.1 1.2 2.1 2.2 3.1 3.2 @end group @end example The fully-written command to start Chapter 2 would be this: @example @group @@node Chapter 2, Chapter 3, Chapter 1, Top @@comment node-name, next, previous, up @end group @end example @noindent This @code{@@node} line says that the name of this node is ``Chapter 2'', the name of the `Next' node is ``Chapter 3'', the name of the `Previous' node is ``Chapter 1'', and the name of the `Up' node is ``Top''. You can omit writing out these node names if your document is hierarchically organized (@pxref{makeinfo Pointer Creation}), but the pointer relationships still obtain. @quotation Note @strong{Please Note:} `Next' refers to the next node at the same hierarchical level in the manual, not necessarily to the next node within the Texinfo file. In the Texinfo file, the subsequent node may be at a lower level---a section-level node most often follows a chapter-level node, for example. `Next' and `Previous' refer to nodes at the @emph{same} hierarchical level. (The `Top' node contains the exception to this rule. Since the `Top' node is the only node at that level, `Next' refers to the first following node, which is almost always a chapter or chapter-level node.)@refill @end quotation To go to Sections 2.1 and 2.2 using Info, you need a menu inside Chapter 2. (@xref{Menus}.) You would write the menu just before the beginning of Section 2.1, like this:@refill @example @group @@menu * Sect. 2.1:: Description of this section. * Sect. 2.2:: @@end menu @end group @end example Write the node for Sect. 2.1 like this:@refill @example @group @@node Sect. 2.1, Sect. 2.2, Chapter 2, Chapter 2 @@comment node-name, next, previous, up @end group @end example In Info format, the `Next' and `Previous' pointers of a node usually lead to other nodes at the same level---from chapter to chapter or from section to section (sometimes, as shown, the `Previous' pointer points up); an `Up' pointer usually leads to a node at the level above (closer to the `Top' node); and a `Menu' leads to nodes at a level below (closer to `leaves'). (A cross reference can point to a node at any level; see @ref{Cross References}.)@refill Usually, an @code{@@node} command and a chapter structuring command are used in sequence, along with indexing commands. (You may follow the @code{@@node} line with a comment line that reminds you which pointer is which.)@refill Here is the beginning of the chapter in this manual called ``Ending a Texinfo File''. This shows an @code{@@node} line followed by a comment line, an @code{@@chapter} line, and then by indexing lines.@refill @example @group @@node Ending a File, Structuring, Beginning a File, Top @@comment node-name, next, previous, up @@chapter Ending a Texinfo File @@cindex Ending a Texinfo file @@cindex Texinfo file ending @@cindex File ending @end group @end example @node node @section The @code{@@node} Command @cindex Node, defined @findex node A @dfn{node} is a segment of text that begins at an @code{@@node} command and continues until the next @code{@@node} command. The definition of node is different from that for chapter or section. A chapter may contain sections and a section may contain subsections; but a node cannot contain subnodes; the text of a node continues only until the next @code{@@node} command in the file. A node usually contains only one chapter structuring command, the one that follows the @code{@@node} line. On the other hand, in printed output nodes are used only for cross references, so a chapter or section may contain any number of nodes. Indeed, a chapter usually contains several nodes, one for each section, subsection, and subsubsection. To create a node, write an @code{@@node} command at the beginning of a line, and follow it with up to four arguments, separated by commas, on the rest of the same line. The first argument is required; it is the name of this node. The subsequent arguments are the names of the `Next', `Previous', and `Up' pointers, in that order, and may be omitted if your Texinfo document is hierarchically organized (@pxref{makeinfo Pointer Creation}). You may insert spaces before each name if you wish; the spaces are ignored. You must write the name of the node and (if present) the names of the `Next', `Previous', and `Up' pointers all on the same line. Otherwise, the formatters fail. (@inforef{Top, info, info}, for more information about nodes in Info.) Usually, you write one of the chapter-structuring command lines immediately after an @code{@@node} line---for example, an @code{@@section} or @code{@@subsection} line. (@xref{Structuring Command Types}.) @quotation Note The GNU Emacs Texinfo mode updating commands work only with Texinfo files in which @code{@@node} lines are followed by chapter structuring lines. @xref{Updating Requirements}. @end quotation @TeX{} uses @code{@@node} lines to identify the names to use for cross references. For this reason, you must write @code{@@node} lines in a Texinfo file that you intend to format for printing, even if you do not intend to format it for Info. (Cross references, such as the one at the end of this sentence, are made with @code{@@xref} and related commands; see @ref{Cross References}.) @menu * Node Names:: How to choose node and pointer names. * Writing a Node:: How to write an @code{@@node} line. * Node Line Tips:: Keep names short. * Node Line Requirements:: Keep names unique, without @@-commands. * First Node:: How to write a `Top' node. * makeinfo top command:: How to use the @code{@@top} command. @end menu @node Node Names @subsection Choosing Node and Pointer Names @cindex Node names, choosing The name of a node identifies the node. The pointers enable you to reach other nodes and consist simply of the names of those nodes. Normally, a node's `Up' pointer contains the name of the node whose menu mentions that node. The node's `Next' pointer contains the name of the node that follows that node in that menu and its `Previous' pointer contains the name of the node that precedes it in that menu. When a node's `Previous' node is the same as its `Up' node, both node pointers name the same node. Usually, the first node of a Texinfo file is the `Top' node, and its `Up' and `Previous' pointers point to the @file{dir} file, which contains the main menu for all of Info. The `Top' node itself contains the main or master menu for the manual. Also, it is helpful to include a brief description of the manual in the `Top' node. @xref{First Node}, for information on how to write the first node of a Texinfo file. Even when you explicitly specify all pointers, that does not mean you can write the nodes in the Texinfo source file in an arbitrary order! Because @TeX{} processes the file sequentially, irrespective of node pointers, you must write the nodes in the order you wish them to appear in the printed output. @node Writing a Node @subsection How to Write an @code{@@node} Line @cindex Writing an @code{@@node} line @cindex @code{@@node} line writing @cindex Node line writing The easiest way to write an @code{@@node} line is to write @code{@@node} at the beginning of a line and then the name of the node, like this:@refill @example @@node @var{node-name} @end example If you are using GNU Emacs, you can use the update node commands provided by Texinfo mode to insert the names of the pointers; or you can leave the pointers out of the Texinfo file and let @code{makeinfo} insert node pointers into the Info file it creates. (@xref{Texinfo Mode}, and @ref{makeinfo Pointer Creation}.)@refill Alternatively, you can insert the `Next', `Previous', and `Up' pointers yourself. If you do this, you may find it helpful to use the Texinfo mode keyboard command @kbd{C-c C-c n}. This command inserts @samp{@@node} and a comment line listing the names of the pointers in their proper order. The comment line helps you keep track of which arguments are for which pointers. This comment line is especially useful if you are not familiar with Texinfo.@refill The template for a fully-written-out node line with `Next', `Previous', and `Up' pointers looks like this:@refill @example @@node @var{node-name}, @var{next}, @var{previous}, @var{up} @end example If you wish, you can ignore @code{@@node} lines altogether in your first draft and then use the @code{texinfo-insert-node-lines} command to create @code{@@node} lines for you. However, we do not recommend this practice. It is better to name the node itself at the same time that you write a segment so you can easily make cross references. A large number of cross references are an especially important feature of a good Info file. After you have inserted an @code{@@node} line, you should immediately write an @@-command for the chapter or section and insert its name. Next (and this is important!), put in several index entries. Usually, you will find at least two and often as many as four or five ways of referring to the node in the index. Use them all. This will make it much easier for people to find the node. @node Node Line Tips @subsection @code{@@node} Line Tips Here are three suggestions: @itemize @bullet @item Try to pick node names that are informative but short.@refill In the Info file, the file name, node name, and pointer names are all inserted on one line, which may run into the right edge of the window. (This does not cause a problem with Info, but is ugly.)@refill @item Try to pick node names that differ from each other near the beginnings of their names. This way, it is easy to use automatic name completion in Info.@refill @item By convention, node names are capitalized just as they would be for section or chapter titles---initial and significant words are capitalized; others are not.@refill @end itemize @node Node Line Requirements @subsection @code{@@node} Line Requirements @cindex Node line requirements @cindex Restrictions on node names Here are several requirements for @code{@@node} lines: @itemize @bullet @cindex Unique nodename requirement @cindex Node name must be unique @item All the node names for a single Info file must be unique. Duplicates confuse the Info movement commands. This means, for example, that if you end every chapter with a summary, you must name each summary node differently. You cannot just call each one ``Summary''. You may, however, duplicate the titles of chapters, sections, and the like. Thus you can end each chapter in a book with a section called ``Summary'', so long as the node names for those sections are all different. @item A pointer name must be the name of a node. The node to which a pointer points may come before or after the node containing the pointer. @cindex @@-commands in nodename @cindex Node name, should not contain @@-commands @item @@-commands in node names are not allowed. This includes punctuation characters that are escaped with a @samp{@@}, such as @code{@@} and @code{@{}, and accent commands such as @samp{@@'}. (For a few cases when this is useful, Texinfo has limited support for using @w{@@-commands} in node names; see @ref{Pointer Validation}.) Perhaps this limitation will be removed some day. @item @cindex Colon in nodename @cindex Comma in nodename @cindex Parentheses in nodename @cindex Period in nodename @cindex Characters, invalid in node name @cindex Invalid characters in node names @cindex Node names, invalid characters in Unfortunately, you cannot use periods, commas, colons or parentheses within a node name; these confuse the Texinfo processors. Perhaps this limitation will be removed some day, too. @need 700 For example, the following is a section title in this manual: @smallexample @@code@{@@@@unnumberedsec@}, @@code@{@@@@appendixsec@}, @@code@{@@@@heading@} @end smallexample @noindent But the corresponding node name lacks the commas and the @@'s: @smallexample unnumberedsec appendixsec heading @end smallexample @cindex Case in node name @item Case is significant in node names. @cindex White space in node name @cindex Spaces in node name Spaces before and after names on the @samp{@@node} line are ignored, but spaces ``inside'' a name are significant. For example: @example @@node foo bar, @@node foo bar , @@node foo bar , @end example @noindent all define the same node, @samp{foo bar}. References to the node should all use that name, without the leading or trailing spaces, but with the internal spaces. @end itemize @node First Node @subsection The First Node @cindex Top node is first @cindex First node The first node of a Texinfo file is the @dfn{Top} node, except in an included file (@pxref{Include Files}). The Top node should contain a short summary, copying permissions, and a master menu. @xref{The Top Node}, for more information on the Top node contents and examples. Here is a description of the node pointers to be used in the Top node: @itemize @bullet @item @cindex Up node of Top node @cindex (dir) as Up node of Top node The Top node (which must be named @samp{top} or @samp{Top}) should have as its `Up' node the name of a node in another file, where there is a menu that leads to this file. Specify the file name in parentheses. Usually, all Info files are installed in the same Info directory tree; in this case, use @samp{(dir)} as the parent of the Top node; this is short for @samp{(dir)top}, and specifies the Top node in the @file{dir} file, which contains the main menu for the Info system as a whole. @item @cindex Previous node of Top node On the other hand, do not define the `Previous' node of the Top node to be @samp{(dir)}, as it causes confusing behavior for users: if you are in the Top node and hits @key{DEL} to go backwards, you wind up in the middle of the some other entry in the @file{dir} file, which has nothing to do with what you were reading. @item @cindex Next node of Top node The `Next' node of the Top node should be the first chapter in your document. @end itemize @xref{Installing an Info File}, for more information about installing an Info file in the @file{info} directory. For concreteness, here is an example with explicit pointers (which you can maintain automatically with the texinfo mode commands): Or you can leave the pointers off entirely and let the tools implicitly define them. This is recommended. Thus: @example @@node Top @end example @node makeinfo top command @subsection The @code{@@top} Sectioning Command @findex top @r{(@@-command)} A special sectioning command, @code{@@top} should be used with the @code{@@node Top} line. The @code{@@top} sectioning command tells @code{makeinfo} that it marks the `Top' node in the file. It provides the information that @code{makeinfo} needs to insert node pointers automatically. Write the @code{@@top} command at the beginning of the line immediately following the @code{@@node Top} line. Write the title on the remaining part of the same line as the @code{@@top} command. In Info, the @code{@@top} sectioning command causes the title to appear on a line by itself, with a line of asterisks inserted underneath, as other sectioning commands do. In @TeX{} and @code{texinfo-format-buffer}, the @code{@@top} sectioning command is merely a synonym for @code{@@unnumbered}. Neither of these formatters require an @code{@@top} command, and do nothing special with it. You can use @code{@@chapter} or @code{@@unnumbered} after the @code{@@node Top} line when you use these formatters. Also, you can use @code{@@chapter} or @code{@@unnumbered} when you use the Texinfo updating commands to create or update pointers and menus. Thus, in practice, a Top node starts like this: @example @@node Top @@top Your Manual Title @end example @node makeinfo Pointer Creation @section Creating Pointers with @code{makeinfo} @cindex Creating pointers with @code{makeinfo} @cindex Pointer creation with @code{makeinfo} @cindex Automatic pointer creation with @code{makeinfo} The @code{makeinfo} program has a feature for automatically determining node pointers for a hierarchically organized document. When you take advantage of this feature, you do not need to write the `Next', `Previous', and `Up' pointers after the name of a node. However, you must write a sectioning command, such as @code{@@chapter} or @code{@@section}, on the line immediately following each truncated @code{@@node} line (except that comment lines may intervene). In addition, you must follow the `Top' @code{@@node} line with a line beginning with @code{@@top} to mark the `Top' node in the file. @xref{makeinfo top, , @code{@@top}}. Finally, you must write the name of each node (except for the `Top' node) in a menu that is one or more hierarchical levels above the node's hierarchical level. This implicit node pointer insertion feature in @code{makeinfo} relieves you from the need to update menus and pointers manually or with Texinfo mode commands. (@xref{Updating Nodes and Menus}.) In most cases, you will want to take advantage of this feature and not redundantly specify node pointers. However, Texinfo documents are not required to be organized hierarchically or in fact to contain sectioning commands at all (for example, if you never intend the document to be printed). The special procedure for handling the short text before a menu (@pxref{Menus}) also disables this feature, for that group of nodes. In those cases, you will need to explicitly specify the pointers. @node anchor @section @code{@@anchor}: Defining Arbitrary Cross-reference Targets @findex anchor @cindex Anchors @cindex Cross-reference targets, arbitrary @cindex Targets for cross-references, arbitrary An @dfn{anchor} is a position in your document, labeled so that cross-references can refer to it, just as they can to nodes. You create an anchor with the @code{@@anchor} command, and give the label as a normal brace-delimited argument. For example: @example This marks the @@anchor@{x-spot@}spot. @dots{} @@xref@{x-spot,,the spot@}. @end example @noindent produces: @example This marks the spot. @dots{} See [the spot], page 1. @end example As you can see, the @code{@@anchor} command itself produces no output. This example defines an anchor `x-spot' just before the word `spot'. You can refer to it later with an @code{@@xref} or other cross-reference command, as shown. @xref{Cross References}, for details on the cross-reference commands. It is best to put @code{@@anchor} commands just before the position you wish to refer to; that way, the reader's eye is led on to the correct text when they jump to the anchor. You can put the @code{@@anchor} command on a line by itself if that helps readability of the source. Spaces are always ignored after @code{@@anchor}. Anchor names and node names may not conflict. Anchors and nodes are given similar treatment in some ways; for example, the @code{goto-node} command in standalone Info takes either an anchor name or a node name as an argument. (@xref{goto-node,,,info-stnd,GNU Info}.) @node Menus @chapter Menus @cindex Menus @findex menu @dfn{Menus} contain pointers to subordinate nodes. In online output, you use menus to go to such nodes. Menus have no effect in printed manuals and do not appear in them. A node with a menu should not contain much text. If you find yourself writing a lot of before a menu, we generally recommend moving most of the text into a new subnode---all but a paragraph or two. Otherwise, a reader with a terminal that displays only a few lines may miss the menu and its associated text. As a practical matter, it is best to locate a menu within 20 or so lines of the beginning of the node. @menu * Menu Location:: Menus go at the ends of short nodes. * Writing a Menu:: What is a menu? * Menu Parts:: A menu entry has three parts. * Less Cluttered Menu Entry:: Two part menu entry. * Menu Example:: Two and three part menu entries. * Other Info Files:: How to refer to a different Info file. @end menu @node Menu Location @section Menu Location @cindex Menu location @cindex Location of menus A menu must be located at the end of a node, without any regular text or additional commands between the @code{@@end menu} and the beginning of the next node. (As a consequence, there may be at most one menu in a node.) @cindex Info format, and menus This is actually a useful restriction, since a reader who uses the menu could easily miss any such text. Technically, it is necessary because in Info format, there is no marker for the end of a menu, so Info-reading programs would have no way to know when the menu ends and normal text resumes. @cindex Hierarchical documents, and menus Technically, menus can carry you to any node, regardless of the structure of the document; even to nodes in a different Info file. However, we do not recommend ever making use of this, because the @command{makeinfo} implicit pointer creation feature (@pxref{makeinfo Pointer Creation}) and GNU Emacs Texinfo mode updating commands work only to create menus of subordinate nodes in a hierarchically structured document. Instead, use cross references to refer to arbitrary nodes. In the past, we recommended using a @samp{@@heading} command within an @code{@@ifinfo} conditional instead of the normal sectioning commands after a very short node with a menu. This had the advantage of making the printed output look better, because there was no very short text between two headings on the page. But aside from not working with @command{makeinfo}'s implicit pointer creation, it also makes the XML output incorrect, since it does not reflect the true document structure. So, unfortunately we can no longer recommend this. @node Writing a Menu @section Writing a Menu @cindex Writing a menu @cindex Menu writing A menu consists of an @code{@@menu} command on a line by itself followed by menu entry lines or menu comment lines and then by an @code{@@end menu} command on a line by itself. A menu looks like this: @example @group @@menu Larger Units of Text * Files:: All about handling files. * Multiples: Buffers. Multiple buffers; editing several files at once. @@end menu @end group @end example In a menu, every line that begins with an @w{@samp{* }} is a @dfn{menu entry}. (Note the space after the asterisk.) A line that does not start with an @w{@samp{* }} may also appear in a menu. Such a line is not a menu entry but is a menu comment line that appears in the Info file. In the example above, the line @samp{Larger Units of Text} is a menu comment line; the two lines starting with @w{@samp{* }} are menu @cindex Spaces, in menus entries. Space characters in a menu are preserved as-is; this allows you to format the menu as you wish. @node Menu Parts @section The Parts of a Menu @cindex Parts of a menu @cindex Menu parts @cindex @code{@@menu} parts A menu entry has three parts, only the second of which is required: @enumerate @item The menu entry name (optional). @item The name of the node (required). @item A description of the item (optional). @end enumerate The template for a menu entry looks like this:@refill @example * @var{menu-entry-name}: @var{node-name}. @var{description} @end example Follow the menu entry name with a single colon and follow the node name with tab, comma, period, or newline.@refill In Info, a user selects a node with the @kbd{m} (@code{Info-menu}) command. The menu entry name is what the user types after the @kbd{m} command.@refill The third part of a menu entry is a descriptive phrase or sentence. Menu entry names and node names are often short; the description explains to the reader what the node is about. A useful description complements the node name rather than repeats it. The description, which is optional, can spread over two or more lines; if it does, some authors prefer to indent the second line while others prefer to align it with the first (and all others). It's up to you. @node Less Cluttered Menu Entry @comment node-name, next, previous, up @section Less Cluttered Menu Entry @cindex Two part menu entry @cindex Double-colon menu entries @cindex Menu entries with two colons @cindex Less cluttered menu entry @cindex Uncluttered menu entry When the menu entry name and node name are the same, you can write the name immediately after the asterisk and space at the beginning of the line and follow the name with two colons.@refill @need 800 For example, write @example * Name:: @var{description} @end example @need 800 @noindent instead of @example * Name: Name. @var{description} @end example You should use the node name for the menu entry name whenever possible, since it reduces visual clutter in the menu.@refill @node Menu Example @comment node-name, next, previous, up @section A Menu Example @cindex Menu example @cindex Example menu A menu looks like this in Texinfo:@refill @example @group @@menu * menu entry name: Node name. A short description. * Node name:: This form is preferred. @@end menu @end group @end example @need 800 @noindent This produces: @example @group * menu: * menu entry name: Node name. A short description. * Node name:: This form is preferred. @end group @end example @need 700 Here is an example as you might see it in a Texinfo file:@refill @example @group @@menu Larger Units of Text * Files:: All about handling files. * Multiples: Buffers. Multiple buffers; editing several files at once. @@end menu @end group @end example @need 800 @noindent This produces: @example @group * menu: Larger Units of Text * Files:: All about handling files. * Multiples: Buffers. Multiple buffers; editing several files at once. @end group @end example In this example, the menu has two entries. @samp{Files} is both a menu entry name and the name of the node referred to by that name. @samp{Multiples} is the menu entry name; it refers to the node named @samp{Buffers}. The line @samp{Larger Units of Text} is a comment; it appears in the menu, but is not an entry.@refill Since no file name is specified with either @samp{Files} or @samp{Buffers}, they must be the names of nodes in the same Info file (@pxref{Other Info Files, , Referring to Other Info Files}).@refill @node Other Info Files @comment node-name, next, previous, up @section Referring to Other Info Files @cindex Referring to other Info files @cindex Nodes in other Info files @cindex Other Info files' nodes @cindex Going to other Info files' nodes @cindex Info; other files' nodes You can create a menu entry that enables a reader in Info to go to a node in another Info file by writing the file name in parentheses just before the node name. In this case, you should use the three-part menu entry format, which saves the reader from having to type the file name.@refill @need 800 The format looks like this:@refill @example @group @@menu * @var{first-entry-name}:(@var{filename})@var{nodename}. @var{description} * @var{second-entry-name}:(@var{filename})@var{second-node}. @var{description} @@end menu @end group @end example For example, to refer directly to the @samp{Outlining} and @samp{Rebinding} nodes in the @cite{Emacs Manual}, you would write a menu like this:@refill @example @group @@menu * Outlining: (emacs)Outline Mode. The major mode for editing outlines. * Rebinding: (emacs)Rebinding. How to redefine the meaning of a key. @@end menu @end group @end example If you do not list the node name, but only name the file, then Info presumes that you are referring to the `Top' node.@refill The @file{dir} file that contains the main menu for Info has menu entries that list only file names. These take you directly to the `Top' nodes of each Info document. (@xref{Installing an Info File}.) @need 700 For example: @example @group * Info: (info). Documentation browsing system. * Emacs: (emacs). The extensible, self-documenting text editor. @end group @end example @noindent (The @file{dir} top level directory for the Info system is an Info file, not a Texinfo file, but a menu entry looks the same in both types of file.)@refill The GNU Emacs Texinfo mode menu updating commands only work with nodes within the current buffer, so you cannot use them to create menus that refer to other files. You must write such menus by hand. @node Cross References @chapter Cross References @cindex Making cross references @cindex Cross references @cindex References @dfn{Cross references} are used to refer the reader to other parts of the same or different Texinfo files. In Texinfo, nodes and anchors are the places to which cross references can refer. @menu * References:: What cross references are for. * Cross Reference Commands:: A summary of the different commands. * Cross Reference Parts:: A cross reference has several parts. * xref:: Begin a reference with `See' @dots{} * Top Node Naming:: How to refer to the beginning of another file. * ref:: A reference for the last part of a sentence. * pxref:: How to write a parenthetical cross reference. * inforef:: How to refer to an Info-only file. * uref:: How to refer to a uniform resource locator. @end menu @node References @section What References Are For Often, but not always, a printed document should be designed so that it can be read sequentially. People tire of flipping back and forth to find information that should be presented to them as they need it.@refill However, in any document, some information will be too detailed for the current context, or incidental to it; use cross references to provide access to such information. Also, an online help system or a reference manual is not like a novel; few read such documents in sequence from beginning to end. Instead, people look up what they need. For this reason, such creations should contain many cross references to help readers find other information that they may not have read.@refill In a printed manual, a cross reference results in a page reference, unless it is to another manual altogether, in which case the cross reference names that manual.@refill In Info, a cross reference results in an entry that you can follow using the Info @samp{f} command. (@inforef{Help-Xref, Following cross-references, info}.) The various cross reference commands use nodes (or anchors, @pxref{anchor,,@code{@@anchor}}) to define cross reference locations. This is evident in Info, in which a cross reference takes you to the specified location. @TeX{} also uses nodes to define cross reference locations, but the action is less obvious. When @TeX{} generates a DVI file, it records each node's page number and uses the page numbers in making references. Thus, if you are writing a manual that will only be printed, and will not be used online, you must nonetheless write @code{@@node} lines to name the places to which you make cross references.@refill @need 800 @node Cross Reference Commands @comment node-name, next, previous, up @section Different Cross Reference Commands @cindex Different cross reference commands There are four different cross reference commands:@refill @table @code @item @@xref Used to start a sentence in the printed manual saying @w{`See @dots{}'} or an Info cross-reference saying @samp{*Note @var{name}: @var{node}.}. @item @@ref Used within or, more often, at the end of a sentence; same as @code{@@xref} for Info; produces just the reference in the printed manual without a preceding `See'.@refill @item @@pxref Used within parentheses to make a reference that suits both an Info file and a printed book. Starts with a lower case `see' within the printed manual. (@samp{p} is for `parenthesis'.)@refill @item @@inforef Used to make a reference to an Info file for which there is no printed manual.@refill @end table @noindent (The @code{@@cite} command is used to make references to books and manuals for which there is no corresponding Info file and, therefore, no node to which to point. @xref{cite, , @code{@@cite}}.)@refill @node Cross Reference Parts @comment node-name, next, previous, up @section Parts of a Cross Reference @cindex Cross reference parts @cindex Parts of a cross reference A cross reference command requires only one argument, which is the name of the node to which it refers. But a cross reference command may contain up to four additional arguments. By using these arguments, you can provide a cross reference name for Info, a topic description or section title for the printed output, the name of a different Info file, and the name of a different printed manual.@refill Here is a simple cross reference example:@refill @example @@xref@{Node name@}. @end example @noindent which produces @example *Note Node name::. @end example @noindent and @quotation See Section @var{nnn} [Node name], page @var{ppp}. @end quotation @need 700 Here is an example of a full five-part cross reference:@refill @example @group @@xref@{Node name, Cross Reference Name, Particular Topic, info-file-name, A Printed Manual@}, for details. @end group @end example @noindent which produces @example *Note Cross Reference Name: (info-file-name)Node name, for details. @end example @noindent in Info and @quotation See section ``Particular Topic'' in @i{A Printed Manual}, for details. @end quotation @noindent in a printed book. The five possible arguments for a cross reference are:@refill @enumerate @item The node or anchor name (required). This is the location to which the cross reference takes you. In a printed document, the location of the node provides the page reference only for references within the same document.@refill @item The cross reference name for the Info reference, if it is to be different from the node name. If you include this argument, it becomes the first part of the cross reference. It is usually omitted.@refill @item A topic description or section name. Often, this is the title of the section. This is used as the name of the reference in the printed manual. If omitted, the node name is used.@refill @item The name of the Info file in which the reference is located, if it is different from the current file. You need not include any @samp{.info} suffix on the file name, since Info readers try appending it automatically. @item The name of a printed manual from a different Texinfo file.@refill @end enumerate The template for a full five argument cross reference looks like this:@refill @example @group @@xref@{@var{node-name}, @var{cross-reference-name}, @var{title-or-topic}, @var{info-file-name}, @var{printed-manual-title}@}. @end group @end example Cross references with one, two, three, four, and five arguments are described separately following the description of @code{@@xref}.@refill Write a node name in a cross reference in exactly the same way as in the @code{@@node} line, including the same capitalization; otherwise, the formatters may not find the reference.@refill You can write cross reference commands within a paragraph, but note how Info and @TeX{} format the output of each of the various commands: write @code{@@xref} at the beginning of a sentence; write @code{@@pxref} only within parentheses, and so on.@refill @node xref @comment node-name, next, previous, up @section @code{@@xref} @findex xref @cindex Cross references using @code{@@xref} @cindex References using @code{@@xref} The @code{@@xref} command generates a cross reference for the beginning of a sentence. The Info formatting commands convert it into an Info cross reference, which the Info @samp{f} command can use to bring you directly to another node. The @TeX{} typesetting commands convert it into a page reference, or a reference to another book or manual.@refill @menu * Reference Syntax:: What a reference looks like and requires. * One Argument:: @code{@@xref} with one argument. * Two Arguments:: @code{@@xref} with two arguments. * Three Arguments:: @code{@@xref} with three arguments. * Four and Five Arguments:: @code{@@xref} with four and five arguments. @end menu @node Reference Syntax @subsection What a Reference Looks Like and Requires Most often, an Info cross reference looks like this:@refill @example *Note @var{node-name}::. @end example @noindent or like this @example *Note @var{cross-reference-name}: @var{node-name}. @end example @noindent In @TeX{}, a cross reference looks like this: @quotation See Section @var{section-number} [@var{node-name}], page @var{page}. @end quotation @noindent or like this @quotation See Section @var{section-number} [@var{title-or-topic}], page @var{page}. @end quotation The @code{@@xref} command does not generate a period or comma to end the cross reference in either the Info file or the printed output. You must write that period or comma yourself; otherwise, Info will not recognize the end of the reference. (The @code{@@pxref} command works differently. @xref{pxref, , @code{@@pxref}}.)@refill @quotation Caution A period or comma @strong{must} follow the closing brace of an @code{@@xref}. It is required to terminate the cross reference. This period or comma will appear in the output, both in the Info file and in the printed manual.@refill @end quotation @code{@@xref} must refer to an Info node by name. Use @code{@@node} to define the node (@pxref{Writing a Node}).@refill @code{@@xref} is followed by several arguments inside braces, separated by commas. Whitespace before and after these commas is ignored.@refill A cross reference requires only the name of a node; but it may contain up to four additional arguments. Each of these variations produces a cross reference that looks somewhat different.@refill @quotation Note Commas separate arguments in a cross reference; avoid including them in the title or other part lest the formatters mistake them for separators.@refill @end quotation @node One Argument @subsection @code{@@xref} with One Argument The simplest form of @code{@@xref} takes one argument, the name of another node in the same Info file. The Info formatters produce output that the Info readers can use to jump to the reference; @TeX{} produces output that specifies the page and section number for you.@refill @need 700 @noindent For example, @example @@xref@{Tropical Storms@}. @end example @noindent produces @example *Note Tropical Storms::. @end example @noindent and @quotation See Section 3.1 [Tropical Storms], page 24. @end quotation @noindent (Note that in the preceding example the closing brace is followed by a period.)@refill You can write a clause after the cross reference, like this:@refill @example @@xref@{Tropical Storms@}, for more info. @end example @noindent which produces @example *Note Tropical Storms::, for more info. @end example @noindent and @quotation See Section 3.1 [Tropical Storms], page 24, for more info. @end quotation @noindent (Note that in the preceding example the closing brace is followed by a comma, and then by the clause, which is followed by a period.)@refill @node Two Arguments @subsection @code{@@xref} with Two Arguments With two arguments, the second is used as the name of the Info cross reference, while the first is still the name of the node to which the cross reference points.@refill @need 750 @noindent The template is like this: @example @@xref@{@var{node-name}, @var{cross-reference-name}@}. @end example @need 700 @noindent For example, @example @@xref@{Electrical Effects, Lightning@}. @end example @noindent produces: @example *Note Lightning: Electrical Effects. @end example @noindent and @quotation See Section 5.2 [Electrical Effects], page 57. @end quotation @noindent (Note that in the preceding example the closing brace is followed by a period; and that the node name is printed, not the cross reference name.) You can write a clause after the cross reference, like this:@refill @example @@xref@{Electrical Effects, Lightning@}, for more info. @end example @noindent which produces @example *Note Lightning: Electrical Effects, for more info. @end example @noindent and @quotation See Section 5.2 [Electrical Effects], page 57, for more info. @end quotation @noindent (Note that in the preceding example the closing brace is followed by a comma, and then by the clause, which is followed by a period.)@refill @node Three Arguments @subsection @code{@@xref} with Three Arguments A third argument replaces the node name in the @TeX{} output. The third argument should be the name of the section in the printed output, or else state the topic discussed by that section. Often, you will want to use initial upper case letters so it will be easier to read when the reference is printed. Use a third argument when the node name is unsuitable because of syntax or meaning.@refill Remember to avoid placing a comma within the title or topic section of a cross reference, or within any other section. The formatters divide cross references into arguments according to the commas; a comma within a title or other section will divide it into two arguments. In a reference, you need to write a title such as ``Clouds, Mist, and Fog'' without the commas.@refill Also, remember to write a comma or period after the closing brace of an @code{@@xref} to terminate the cross reference. In the following examples, a clause follows a terminating comma.@refill @need 750 @noindent The template is like this: @example @group @@xref@{@var{node-name}, @var{cross-reference-name}, @var{title-or-topic}@}. @end group @end example @need 700 @noindent For example, @example @group @@xref@{Electrical Effects, Lightning, Thunder and Lightning@}, for details. @end group @end example @noindent produces @example *Note Lightning: Electrical Effects, for details. @end example @noindent and @quotation See Section 5.2 [Thunder and Lightning], page 57, for details. @end quotation If a third argument is given and the second one is empty, then the third argument serves both. (Note how two commas, side by side, mark the empty second argument.)@refill @example @group @@xref@{Electrical Effects, , Thunder and Lightning@}, for details. @end group @end example @noindent produces @example *Note Thunder and Lightning: Electrical Effects, for details. @end example @noindent and @quotation See Section 5.2 [Thunder and Lightning], page 57, for details. @end quotation As a practical matter, it is often best to write cross references with just the first argument if the node name and the section title are the same, and with the first and third arguments if the node name and title are different.@refill Here are several examples from @cite{The GNU Awk User's Guide}:@refill @smallexample @@xref@{Sample Program@}. @@xref@{Glossary@}. @@xref@{Case-sensitivity, ,Case-sensitivity in Matching@}. @@xref@{Close Output, , Closing Output Files and Pipes@}, for more information. @@xref@{Regexp, , Regular Expressions as Patterns@}. @end smallexample @node Four and Five Arguments @subsection @code{@@xref} with Four and Five Arguments In a cross reference, a fourth argument specifies the name of another Info file, different from the file in which the reference appears, and a fifth argument specifies its title as a printed manual.@refill Remember that a comma or period must follow the closing brace of an @code{@@xref} command to terminate the cross reference. In the following examples, a clause follows a terminating comma.@refill @need 800 @noindent The template is: @example @group @@xref@{@var{node-name}, @var{cross-reference-name}, @var{title-or-topic}, @var{info-file-name}, @var{printed-manual-title}@}. @end group @end example @need 700 @noindent For example, @example @@xref@{Electrical Effects, Lightning, Thunder and Lightning, weather, An Introduction to Meteorology@}, for details. @end example @noindent produces @example *Note Lightning: (weather)Electrical Effects, for details. @end example @noindent The name of the Info file is enclosed in parentheses and precedes the name of the node. @noindent In a printed manual, the reference looks like this:@refill @quotation See section ``Thunder and Lightning'' in @i{An Introduction to Meteorology}, for details. @end quotation @noindent The title of the printed manual is typeset in italics; and the reference lacks a page number since @TeX{} cannot know to which page a reference refers when that reference is to another manual.@refill Often, you will leave out the second argument when you use the long version of @code{@@xref}. In this case, the third argument, the topic description, will be used as the cross reference name in Info.@refill @noindent The template looks like this: @example @@xref@{@var{node-name}, , @var{title-or-topic}, @var{info-file-name}, @var{printed-manual-title}@}, for details. @end example @noindent which produces @example *Note @var{title-or-topic}: (@var{info-file-name})@var{node-name}, for details. @end example @noindent and @quotation See section @var{title-or-topic} in @var{printed-manual-title}, for details. @end quotation @need 700 @noindent For example, @example @@xref@{Electrical Effects, , Thunder and Lightning, weather, An Introduction to Meteorology@}, for details. @end example @noindent produces @example @group *Note Thunder and Lightning: (weather)Electrical Effects, for details. @end group @end example @noindent and @quotation See section ``Thunder and Lightning'' in @i{An Introduction to Meteorology}, for details. @end quotation On rare occasions, you may want to refer to another Info file that is within a single printed manual---when multiple Texinfo files are incorporated into the same @TeX{} run but make separate Info files. In this case, you need to specify only the fourth argument, and not the fifth.@refill @node Top Node Naming @section Naming a `Top' Node @cindex Naming a `Top' Node in references @cindex @samp{@r{Top}} node naming for references In a cross reference, you must always name a node. This means that in order to refer to a whole manual, you must identify the `Top' node by writing it as the first argument to the @code{@@xref} command. (This is different from the way you write a menu entry; see @ref{Other Info Files, , Referring to Other Info Files}.) At the same time, to provide a meaningful section topic or title in the printed cross reference (instead of the word `Top'), you must write an appropriate entry for the third argument to the @code{@@xref} command. @refill @noindent Thus, to make a cross reference to @cite{The GNU Make Manual}, write:@refill @example @@xref@{Top, , Overview, make, The GNU Make Manual@}. @end example @noindent which produces @example *Note Overview: (make)Top. @end example @noindent and @quotation See section ``Overview'' in @i{The GNU Make Manual}. @end quotation @noindent In this example, @samp{Top} is the name of the first node, and @samp{Overview} is the name of the first section of the manual. @node ref @section @code{@@ref} @cindex Cross references using @code{@@ref} @cindex References using @code{@@ref} @findex ref @code{@@ref} is nearly the same as @code{@@xref} except that it does not generate a `See' in the printed output, just the reference itself. This makes it useful as the last part of a sentence. @noindent For example, @cindex Hurricanes @example For more information, see @@ref@{Hurricanes@}. @end example @noindent produces (in Info): @example For more information, see *Note Hurricanes::. @end example @noindent and (in printed output): @quotation For more information, see Section 8.2 [Hurricanes], page 123. @end quotation The @code{@@ref} command sometimes tempts writers to express themselves in a manner that is suitable for a printed manual but looks awkward in the Info format. Bear in mind that your audience will be using both the printed and the Info format. For example: @cindex Sea surges @example Sea surges are described in @@ref@{Hurricanes@}. @end example @noindent looks ok in the printed output: @quotation Sea surges are described in Section 6.7 [Hurricanes], page 72. @end quotation @noindent but is awkward to read in Info: @example Sea surges are described in *Note Hurricanes::. @end example As a general rule, you should write a period or comma immediately after an @code{@@ref} command with two or more arguments. If there is no such following punctuation, @command{makeinfo} will generate a (grammatically incorrect) period in the Info output; otherwise, the cross-reference would fail completely, due to the current syntax of Info format. @node pxref @section @code{@@pxref} @cindex Cross references using @code{@@pxref} @cindex References using @code{@@pxref} @findex pxref The parenthetical reference command, @code{@@pxref}, is nearly the same as @code{@@xref}, but you use it @emph{only} inside parentheses and you do @emph{not} type a comma or period (or anything else) after the command's closing brace. The command differs from @code{@@xref} in two ways: @enumerate @item @TeX{} typesets the reference for the printed manual with a lower case `see' rather than an upper case `See'.@refill @item The Info formatting commands automatically end the reference with a closing colon or period.@refill @end enumerate Because one type of formatting automatically inserts closing punctuation and the other does not, you should use @code{@@pxref} @emph{only} inside parentheses as part of another sentence. Also, you yourself should not insert punctuation after the reference (or any other text), as you do with @code{@@xref}. In the Info output, such text would follow a period, which is grammatically wrong. @code{@@pxref} is designed so that the output looks right and works right between parentheses both in printed output and in an Info file. In a printed manual, a closing comma or period should not follow a cross reference within parentheses; such punctuation is wrong. But in an Info file, suitable closing punctuation must follow the cross reference so Info can recognize its end. @code{@@pxref} spares you the need to use complicated methods to put a terminator into one form of the output and not the other.@refill @noindent With one argument, a parenthetical cross reference looks like this:@refill @cindex Flooding @example @dots{} storms cause flooding (@@pxref@{Hurricanes@}) @dots{} @end example @need 800 @noindent which produces @example @group @dots{} storms cause flooding (*Note Hurricanes::) @dots{} @end group @end example @noindent and @quotation @dots{} storms cause flooding (see Section 6.7 [Hurricanes], page 72) @dots{} @end quotation With two arguments, a parenthetical cross reference has this template:@refill @example @dots{} (@@pxref@{@var{node-name}, @var{cross-reference-name}@}) @dots{} @end example @noindent which produces @example @dots{} (*Note @var{cross-reference-name}: @var{node-name}.) @dots{} @end example @noindent and @need 1500 @quotation @dots{} (see Section @var{nnn} [@var{node-name}], page @var{ppp}) @dots{} @end quotation @code{@@pxref} can be used with up to five arguments just like @code{@@xref} (@pxref{xref, , @code{@@xref}}).@refill @quotation Caution Use @code{@@pxref} only as a parenthetical reference. Do not try to use @code{@@pxref} as a clause in a sentence. It will look bad in either the Info file, the printed output, or both.@refill @end quotation Parenthetical cross references look best at the ends of sentences. Although they technically work in the middle of a sentence, that location breaks up the flow of reading. @node inforef @section @code{@@inforef} @cindex Cross references using @code{@@inforef} @cindex References using @code{@@inforef} @findex inforef @code{@@inforef} is used for making cross references to Info documents---even from a printed manual. This might be because you want to refer to conditional @code{@@ifinfo} text (@pxref{Conditionals}), or because printed output is not available (perhaps because there is no Texinfo source), among other possibilities. The command takes either two or three arguments, in the following order:@refill @enumerate @item The node name. @item The cross reference name (optional). @item The Info file name. @end enumerate @noindent Separate the arguments with commas, as with @code{@@xref}. Also, you must terminate the reference with a comma or period after the @samp{@}}, as you do with @code{@@xref}.@refill @noindent The template is: @example @@inforef@{@var{node-name}, @var{cross-reference-name}, @var{info-file-name}@}, @end example @need 800 @noindent For example, @example @group @@inforef@{Advanced, Advanced Info commands, info@}, for more information. @end group @end example @need 800 @noindent produces (in Info): @example @group *Note Advanced Info commands: (info)Advanced, for more information. @end group @end example @need 800 @noindent and (in the printed output): @quotation See Info file @file{info}, node @samp{Advanced}, for more information. @end quotation (This particular example is not realistic, since the Info manual is written in Texinfo, so all formats are available.) The converse of @code{@@inforef} is @code{@@cite}, which is used to refer to printed works for which no Info form exists. @xref{cite, , @code{@@cite}}. @node uref @section @code{@@url}, @code{@@uref@{@var{url}[, @var{text}][, @var{replacement}]@}} @findex uref @cindex Uniform resource locator, referring to @cindex URL, referring to @cindex @code{href}, producing HTML @code{@@uref} produces a reference to a uniform resource locator (url). It takes one mandatory argument, the url, and two optional arguments which control the text that is displayed. In HTML output, @code{@@uref} produces a link you can follow. @code{@@url} is a synonym for @code{@@uref}. Originally, @code{@@url} had the meaning of @code{@@indicateurl} (@pxref{indicateurl,,@code{@@indicateurl}}), but in actual practice it was misused the vast majority of the time. So we've changed the definitions. The second argument, if specified, is the text to display (the default is the url itself); in Info and DVI output, but not in HTML output, the url is also output. @cindex Man page, reference to The third argument, if specified, is the text to display, but in this case the url is @emph{not} output in any format. This is useful when the text is already sufficiently referential, as in a man page. If the third argument is given, the second argument is ignored. If the url is long enough to cause problems with line breaking, you may find it useful to insert @code{@@/} at places where a line break would be acceptable (after @samp{/} characters, for instance). This tells @TeX{} to allow (but not force) a line break at those places. @xref{Line Breaks}. Here is an example of the simple one argument form, where the url is both the target and the text of the link: @example The official GNU ftp site is @@uref@{ftp://ftp.gnu.org/gnu@}. @end example @noindent produces: @display The official GNU ftp site is @uref{ftp://ftp.gnu.org/gnu}. @end display An example of the two-argument form: @example The official @@uref@{ftp://ftp.gnu.org/gnu, GNU ftp site@} holds programs and texts. @end example @noindent produces: @display The official @uref{ftp://ftp.gnu.org/gnu, GNU ftp site} holds programs and texts. @end display @noindent that is, the Info output is this: @example The official GNU ftp site (ftp://ftp.gnu.org/gnu) holds programs and texts. @end example @noindent and the HTML output is this: @example The official <a href="ftp://ftp.gnu.org/gnu">GNU ftp site</a> holds programs and texts. @end example An example of the three-argument form: @example The @@uref@{/man.cgi/1/ls,,ls(1)@} program @dots{} @end example @noindent produces: @display The @uref{/man.cgi/1/ls,,ls(1)} program @dots{} @end display @noindent but with HTML: @example The <a href="/man.cgi/1/ls">ls(1)</a> program @dots{} @end example To merely indicate a url without creating a link people can follow, use @code{@@indicateurl} (@pxref{indicateurl, @code{@@indicateurl}}). Some people prefer to display url's in the unambiguous format: @display <URL:http://@var{host}/@var{path}> @end display @noindent @cindex <URL: convention, not used You can use this form in the input file if you wish. We feel it's not necessary to include the @samp{<URL:} and @samp{>} in the output, since any software that tries to detect url's in text already has to detect them without the @samp{<URL:} to be useful. @node Marking Text @chapter Marking Words and Phrases @cindex Paragraph, marking text within @cindex Marking words and phrases @cindex Words and phrases, marking them @cindex Marking text within a paragraph @cindex Text, marking up In Texinfo, you can mark words and phrases in a variety of ways. The Texinfo formatters use this information to determine how to highlight the text. You can specify, for example, whether a word or phrase is a defining occurrence, a metasyntactic variable, or a symbol used in a program. Also, you can emphasize text, in several different ways. @menu * Indicating:: How to indicate definitions, files, etc. * Emphasis:: How to emphasize text. @end menu @node Indicating @section Indicating Definitions, Commands, etc. @cindex Highlighting text @cindex Indicating commands, definitions, etc. Texinfo has commands for indicating just what kind of object a piece of text refers to. For example, metasyntactic variables are marked by @code{@@var}, and code by @code{@@code}. Since the pieces of text are labelled by commands that tell what kind of object they are, it is easy to change the way the Texinfo formatters prepare such text. (Texinfo is an @emph{intentional} formatting language rather than a @emph{typesetting} formatting language.)@refill For example, in a printed manual, code is usually illustrated in a typewriter font; @code{@@code} tells @TeX{} to typeset this text in this font. But it would be easy to change the way @TeX{} highlights code to use another font, and this change would not affect how keystroke examples are highlighted. If straight typesetting commands were used in the body of the file and you wanted to make a change, you would need to check every single occurrence to make sure that you were changing code and not something else that should not be changed.@refill @menu * Useful Highlighting:: Highlighting provides useful information. * code:: Indicating program code. * kbd:: Showing keyboard input. * key:: Specifying keys. * samp:: Indicating a literal sequence of characters. * verb:: Indicating a verbatim sequence of characters. * var:: Indicating metasyntactic variables. * env:: Indicating environment variables. * file:: Indicating file names. * command:: Indicating command names. * option:: Indicating option names. * dfn:: Specifying definitions. * cite:: Referring to books not in the Info system. * abbr:: Indicating abbreviations. * acronym:: Indicating acronyms. * indicateurl:: Indicating an example URL. * email:: Indicating an electronic mail address. @end menu @node Useful Highlighting @subsection Highlighting Commands are Useful The highlighting commands can be used to extract useful information from the file, such as lists of functions or file names. It is possible, for example, to write a program in Emacs Lisp (or a keyboard macro) to insert an index entry after every paragraph that contains words or phrases marked by a specified command. You could do this to construct an index of functions if you had not already made the entries.@refill The commands serve a variety of purposes:@refill @table @code @item @@code@{@var{sample-code}@} Indicate text that is a literal example of a piece of a program. @xref{code,,@code{@@code}}. @item @@kbd@{@var{keyboard-characters}@} Indicate keyboard input. @xref{kbd,,@code{@@kbd}}. @item @@key@{@var{key-name}@} Indicate the conventional name for a key on a keyboard. @xref{key,,@code{@@key}}. @item @@samp@{@var{text}@} Indicate text that is a literal example of a sequence of characters. @xref{samp,,@code{@@samp}}. @item @@verb@{@var{text}@} Write a verbatim sequence of characters. @xref{verb,,@code{@@verb}}. @item @@var@{@var{metasyntactic-variable}@} Indicate a metasyntactic variable. @xref{var,,@code{@@var}}. @item @@env@{@var{environment-variable}@} Indicate an environment variable. @xref{env,,@code{@@kenv}}. @item @@file@{@var{file-name}@} Indicate the name of a file. @xref{file,,@code{@@file}}. @item @@command@{@var{command-name}@} Indicate the name of a command. @xref{command,,@code{@@command}}. @item @@option@{@var{option}@} Indicate a command-line option. @xref{option,,@code{@@option}}. @item @@dfn@{@var{term}@} Indicate the introductory or defining use of a term. @xref{dfn,,@code{@@dfn}}. @item @@cite@{@var{reference}@} Indicate the name of a book. @xref{cite,,@code{@@cite}}. @item @@abbr@{@var{abbreviation}@} Indicate an abbreviation. @item @@acronym@{@var{acronym}@} Indicate an acronym. @xref{acronym,,@code{@@acronym}}. @item @@indicateurl@{@var{uniform-resource-locator}@} Indicate an example (that is, nonfunctional) uniform resource locator. @xref{indicateurl,,@code{@@indicateurl}}. (Use @code{@@url} (@pxref{uref,,@code{@@url}}) for live url's.) @item @@email@{@var{email-address}[, @var{displayed-text}]@} Indicate an electronic mail address. @xref{email,,@code{@@email}}. @ignore @item @@ctrl@{@var{ctrl-char}@} Use for an @sc{ascii} control character.@refill @end ignore @end table @node code @subsection @code{@@code}@{@var{sample-code}@} @findex code @cindex Syntactic tokens, indicating Use the @code{@@code} command to indicate text that is a piece of a program and which consists of entire syntactic tokens. Enclose the text in braces. @cindex Expressions in a program, indicating @cindex Keywords, indicating @cindex Reserved words, indicating Thus, you should use @code{@@code} for an expression in a program, for the name of a variable or function used in a program, or for a keyword in a programming language. Use @code{@@code} for command names in languages that resemble programming languages, such as Texinfo. For example, @code{@@code} and @code{@@samp} are produced by writing @samp{@@code@{@@@@code@}} and @samp{@@code@{@@@@samp@}} in the Texinfo source, respectively. @cindex Case, not altering in @code{@@code} It is incorrect to alter the case of a word inside an @code{@@code} command when it appears at the beginning of a sentence. Most computer languages are case sensitive. In C, for example, @code{Printf} is different from the identifier @code{printf}, and most likely is a misspelling of it. Even in languages which are not case sensitive, it is confusing to a human reader to see identifiers spelled in different ways. Pick one spelling and always use that. If you do not want to start a sentence with a command name written all in lower case, you should rearrange the sentence. In the printed manual, @code{@@code} causes @TeX{} to typeset the argument in a typewriter face. In the Info file, it causes the Info formatting commands to use single quotation marks around the text. @need 700 For example, @example The function returns @@code@{nil@}. @end example @noindent produces this in the printed manual: @quotation The function returns @code{nil}. @end quotation @iftex @noindent and this in the Info file: @example The function returns `nil'. @end example @end iftex Here are some cases for which it is preferable not to use @code{@@code}: @itemize @bullet @item For shell command names such as @command{ls} (use @code{@@command}). @item For shell options such as @samp{-c} when such options stand alone (use @code{@@option}). @item Also, an entire shell command often looks better if written using @code{@@samp} rather than @code{@@code}. In this case, the rule is to choose the more pleasing format. @item For environment variable such as @env{TEXINPUTS} (use @code{@@env}). @item For a string of characters shorter than a syntactic token. For example, if you are writing about @samp{goto-ch}, which is just a part of the name for the @code{goto-char} Emacs Lisp function, you should use @code{@@samp}. @item In general, when writing about the characters used in a token; for example, do not use @code{@@code} when you are explaining what letters or printable symbols can be used in the names of functions. (Use @code{@@samp}.) Also, you should not use @code{@@code} to mark text that is considered input to programs unless the input is written in a language that is like a programming language. For example, you should not use @code{@@code} for the keystroke commands of GNU Emacs (use @code{@@kbd} instead) although you may use @code{@@code} for the names of the Emacs Lisp functions that the keystroke commands invoke. @end itemize Since @code{@@command}, @code{@@option}, and @code{@@env} were introduced relatively recently, it is acceptable to use @code{@@code} or @code{@@samp} for command names, options, and environment variables. The new commands allow you to express the markup more precisely, but there is no real harm in using the older commands, and of course the long-standing manuals do so. @node kbd @subsection @code{@@kbd}@{@var{keyboard-characters}@} @findex kbd @cindex Keyboard input Use the @code{@@kbd} command for characters of input to be typed by users. For example, to refer to the characters @kbd{M-a}, write: @example @@kbd@{M-a@} @end example @noindent and to refer to the characters @kbd{M-x shell}, write: @example @@kbd@{M-x shell@} @end example @cindex User input @cindex Slanted typewriter font, for @code{@@kbd} By default, the @code{@@kbd} command produces a different font (slanted typewriter instead of normal typewriter) in the printed manual, so users can distinguish the characters that they are supposed to type from those that the computer outputs. In Info output, @code{@@kbd} is usually the same as @code{@@code}, producing `quotes' around its argument. However, in typewriter-like contexts such as the @code{@@example} environment (@pxref{example}) and @code{@@code} command itself, the quotes are omitted, since Info format cannot use distinguishing fonts. @findex kbdinputstyle Since the usage of @code{@@kbd} varies from manual to manual, you can control the font switching with the @code{@@kbdinputstyle} command. This command has no effect on Info output. Write this command at the beginning of a line with a single word as an argument, one of the following: @vindex distinct@r{, value for @code{@@kbdinputstyle}} @vindex example@r{, value for @code{@@kbdinputstyle}} @vindex code@r{, value for @code{@@kbdinputstyle}} @table @samp @item code Always use the same font for @code{@@kbd} as @code{@@code}. @item example Use the distinguishing font for @code{@@kbd} only in @code{@@example} and similar environments. @item distinct (the default) Always use the distinguishing font for @code{@@kbd}. @end table You can embed another @@-command inside the braces of an @code{@@kbd} command. Here, for example, is the way to describe a command that would be described more verbosely as ``press the @samp{r} key and then press the @key{RETURN} key'': @example @@kbd@{r @@key@{RET@}@} @end example @noindent This produces: @kbd{r @key{RET}}. (The present manual accepts the default for @code{@@kbdinputstyle}.) You also use the @code{@@kbd} command if you are spelling out the letters you type; for example: @example To give the @@code@{logout@} command, type the characters @@kbd@{l o g o u t @@key@{RET@}@}. @end example @noindent This produces: @quotation To give the @code{logout} command, type the characters @kbd{l o g o u t @key{RET}}. @end quotation (Also, this example shows that you can add spaces for clarity. If you explicitly want to mention a space character as one of the characters of input, write @kbd{@@key@{SPC@}} for it.)@refill @node key @comment node-name, next, previous, up @subsection @code{@@key}@{@var{key-name}@} @findex key Use the @code{@@key} command for the conventional name for a key on a keyboard, as in:@refill @example @@key@{RET@} @end example You can use the @code{@@key} command within the argument of an @code{@@kbd} command when the sequence of characters to be typed includes one or more keys that are described by name.@refill @need 700 For example, to produce @kbd{C-x @key{ESC}} you would type:@refill @example @@kbd@{C-x @@key@{ESC@}@} @end example Here is a list of the recommended names for keys: @cindex Recommended names for keys @cindex Keys, recommended names @cindex Names recommended for keys @cindex Abbreviations for keys @quotation @table @t @item SPC Space @item RET Return @item LFD Linefeed (however, since most keyboards nowadays do not have a Linefeed key, it might be better to call this character @kbd{C-j}. @item TAB Tab @item BS Backspace @item ESC Escape @item DEL Delete @item SHIFT Shift @item CTRL Control @item META Meta @end table @end quotation @cindex META key There are subtleties to handling words like `meta' or `ctrl' that are names of modifier keys. When mentioning a character in which the modifier key is used, such as @kbd{Meta-a}, use the @code{@@kbd} command alone; do not use the @code{@@key} command; but when you are referring to the modifier key in isolation, use the @code{@@key} command. For example, write @samp{@@kbd@{Meta-a@}} to produce @kbd{Meta-a} and @samp{@@key@{META@}} to produce @key{META}. @c I don't think this is a good explanation. @c I think it will puzzle readers more than it clarifies matters. -- rms. @c In other words, use @code{@@kbd} for what you do, and use @code{@@key} @c for what you talk about: ``Press @code{@@kbd@{M-a@}} to move point to @c the beginning of the sentence. The @code{@@key@{META@}} key is often in @c the lower left of the keyboard.''@refill @node samp @subsection @code{@@samp}@{@var{text}@} @findex samp Use the @code{@@samp} command to indicate text that is a literal example or `sample' of a sequence of characters in a file, string, pattern, etc. Enclose the text in braces. The argument appears within single quotation marks in both the Info file and the printed manual; in addition, it is printed in a fixed-width font.@refill @example To match @@samp@{foo@} at the end of the line, use the regexp @@samp@{foo$@}. @end example @noindent produces @quotation To match @samp{foo} at the end of the line, use the regexp @samp{foo$}.@refill @end quotation Any time you are referring to single characters, you should use @code{@@samp} unless @code{@@kbd} or @code{@@key} is more appropriate. Also, you may use @code{@@samp} for entire statements in C and for entire shell commands---in this case, @code{@@samp} often looks better than @code{@@code}. Basically, @code{@@samp} is a catchall for whatever is not covered by @code{@@code}, @code{@@kbd}, or @code{@@key}.@refill Only include punctuation marks within braces if they are part of the string you are specifying. Write punctuation marks outside the braces if those punctuation marks are part of the English text that surrounds the string. In the following sentence, for example, the commas and period are outside of the braces:@refill @example @group In English, the vowels are @@samp@{a@}, @@samp@{e@}, @@samp@{i@}, @@samp@{o@}, @@samp@{u@}, and sometimes @@samp@{y@}. @end group @end example @noindent This produces: @quotation In English, the vowels are @samp{a}, @samp{e}, @samp{i}, @samp{o}, @samp{u}, and sometimes @samp{y}. @end quotation @node verb @subsection @code{@@verb}@{<char>@var{text}<char>@} @findex verb @cindex Verbatim in-line text @cindex Delimiter character, for verbatim Use the @code{@@verb} command to print a verbatim sequence of characters. Like @LaTeX{}'s @code{\verb} command, the verbatim text can be quoted using any unique delimiter character. Enclose the verbatim text, including the delimiters, in braces. Text is printed in a fixed-width font: @example How many @@verb@{|@@|@}-escapes does one need to print this @@verb@{.@@a @@b @@c.@} string or @@verb@{+@@'e@?`@!`@{@}\+@} this? @end example @noindent produces @example How many @verb{|@|}-escapes does one need to print this @verb{.@a @b @c.} string or these @verb{+@'e?`{}!`\+} this? @end example This is in contrast to @code{@@samp} (see the previous section), @code{@@code}, and similar commands; in those cases, the argument is normal Texinfo text, where the three characters @code{@@@{@}} are special. With @code{@@verb}, nothing is special except the delimiter character you choose. It is not reliable to use @code{@@verb} inside other Texinfo constructs. In particular, it does not work to use @code{@@verb} in anything related to cross-referencing, such as section titles or figure captions. @node var @subsection @code{@@var}@{@var{metasyntactic-variable}@} @findex var Use the @code{@@var} command to indicate metasyntactic variables. A @dfn{metasyntactic variable} is something that stands for another piece of text. For example, you should use a metasyntactic variable in the documentation of a function to describe the arguments that are passed to that function.@refill Do not use @code{@@var} for the names of particular variables in programming languages. These are specific names from a program, so @code{@@code} is correct for them (@pxref{code}). For example, the Emacs Lisp variable @code{texinfo-tex-command} is not a metasyntactic variable; it is properly formatted using @code{@@code}. Do not use @code{@@var} for environment variables either; @code{@@env} is correct for them (see the next section). The effect of @code{@@var} in the Info file is to change the case of the argument to all upper case. In the printed manual and HTML output, the argument is printed in slanted type. @need 700 For example, @example To delete file @@var@{filename@}, type @@samp@{rm @@var@{filename@}@}. @end example @noindent produces @quotation To delete file @var{filename}, type @samp{rm @var{filename}}. @end quotation @noindent (Note that @code{@@var} may appear inside @code{@@code}, @code{@@samp}, @code{@@file}, etc.)@refill Write a metasyntactic variable all in lower case without spaces, and use hyphens to make it more readable. Thus, the Texinfo source for the illustration of how to begin a Texinfo manual looks like this:@refill @example @group \input texinfo @@@@setfilename @@var@{info-file-name@} @@@@settitle @@var@{name-of-manual@} @end group @end example @noindent This produces: @example @group \input texinfo @@setfilename @var{info-file-name} @@settitle @var{name-of-manual} @end group @end example In some documentation styles, metasyntactic variables are shown with angle brackets, for example:@refill @example @dots{}, type rm <filename> @end example @noindent However, that is not the style that Texinfo uses. (You can, of course, modify the sources to @file{texinfo.tex} and the Info formatting commands to output the @code{<@dots{}>} format if you wish.)@refill @node env @subsection @code{@@env}@{@var{environment-variable}@} @findex env Use the @code{@@env} command to indicate environment variables, as used by many operating systems, including GNU. Do not use it for metasyntactic variables; use @code{@@var} instead (see the previous section). @code{@@env} is equivalent to @code{@@code} in its effects. For example: @example The @@env@{PATH@} environment variable @dots{} @end example @noindent produces @quotation The @env{PATH} environment variable @dots{} @end quotation @node file @subsection @code{@@file}@{@var{file-name}@} @findex file Use the @code{@@file} command to indicate text that is the name of a file, buffer, or directory, or is the name of a node in Info. You can also use the command for file name suffixes. Do not use @code{@@file} for symbols in a programming language; use @code{@@code}. Currently, @code{@@file} is equivalent to @code{@@samp} in its effects. For example,@refill @example The @@file@{.el@} files are in the @@file@{/usr/local/emacs/lisp@} directory. @end example @noindent produces @quotation The @file{.el} files are in the @file{/usr/local/emacs/lisp} directory. @end quotation @node command @subsection @code{@@command}@{@var{command-name}@} @findex command @cindex Command names, indicating @cindex Program names, indicating Use the @code{@@command} command to indicate command names, such as @command{ls} or @command{cc}. @code{@@command} is equivalent to @code{@@code} in its effects. For example: @example The command @@command@{ls@} lists directory contents. @end example @noindent produces @quotation The command @command{ls} lists directory contents. @end quotation You should write the name of a program in the ordinary text font, rather than using @code{@@command}, if you regard it as a new English word, such as `Emacs' or `Bison'. When writing an entire shell command invocation, as in @samp{ls -l}, you should use either @code{@@samp} or @code{@@code} at your discretion. @node option @subsection @code{@@option}@{@var{option-name}@} @findex option Use the @code{@@option} command to indicate a command-line option; for example, @option{-l} or @option{--version} or @option{--output=@var{filename}}. @code{@@option} is equivalent to @code{@@samp} in its effects. For example: @example The option @@option@{-l@} produces a long listing. @end example @noindent produces @quotation The option @option{-l} produces a long listing. @end quotation In tables, putting options inside @code{@@code} produces a more pleasing effect. @node dfn @comment node-name, next, previous, up @subsection @code{@@dfn}@{@var{term}@} @findex dfn Use the @code{@@dfn} command to identify the introductory or defining use of a technical term. Use the command only in passages whose purpose is to introduce a term which will be used again or which the reader ought to know. Mere passing mention of a term for the first time does not deserve @code{@@dfn}. The command generates italics in the printed manual, and double quotation marks in the Info file. For example:@refill @example Getting rid of a file is called @@dfn@{deleting@} it. @end example @noindent produces @quotation Getting rid of a file is called @dfn{deleting} it. @end quotation As a general rule, a sentence containing the defining occurrence of a term should be a definition of the term. The sentence does not need to say explicitly that it is a definition, but it should contain the information of a definition---it should make the meaning clear. @node cite @subsection @code{@@cite}@{@var{reference}@} @findex cite Use the @code{@@cite} command for the name of a book that lacks a companion Info file. The command produces italics in the printed manual, and quotation marks in the Info file. If a book is written in Texinfo, it is better to use a cross reference command since a reader can easily follow such a reference in Info. @xref{xref, , @code{@@xref}}. @ignore @c node ctrl, , cite, Indicating @comment node-name, next, previous, up @c subsection @code{@@ctrl}@{@var{ctrl-char}@} @findex ctrl The @code{@@ctrl} command is seldom used. It describes an @sc{ascii} control character by inserting the actual character into the Info file. Usually, in Texinfo, you talk what you type as keyboard entry by describing it with @code{@@kbd}: thus, @samp{@@kbd@{C-a@}} for @kbd{C-a}. Use @code{@@kbd} in this way when talking about a control character that is typed on the keyboard by the user. When talking about a control character appearing in a file or a string, do not use @code{@@kbd} since the control character is not typed. Also, do not use @samp{C-} but spell out @code{control-}, as in @samp{control-a}, to make it easier for a reader to understand.@refill @code{@@ctrl} is an idea from the beginnings of Texinfo which may not really fit in to the scheme of things. But there may be times when you want to use the command. The pattern is @code{@@ctrl@{@var{ch}@}}, where @var{ch} is an @sc{ascii} character whose control-equivalent is wanted. For example, to specify @samp{control-f}, you would enter@refill @example @@ctrl@{f@} @end example @noindent produces @quotation @ctrl{f} @end quotation In the Info file, this generates the specified control character, output literally into the file. This is done so a user can copy the specified control character (along with whatever else he or she wants) into another Emacs buffer and use it. Since the `control-h',`control-i', and `control-j' characters are formatting characters, they should not be indicated with @code{@@ctrl}.@refill In a printed manual, @code{@@ctrl} generates text to describe or identify that control character: an uparrow followed by the character @var{ch}.@refill @end ignore @node abbr @subsection @code{@@abbr}@{@var{abbreviation}[, @var{meaning}]@} @findex abbr @cindex Abbreviations, tagging You can use the @code{@@abbr} command for general abbreviations. The abbreviation is given as the single argument in braces, as in @samp{@@abbr@{Comput.@}}. As a matter of style, or for particular abbreviations, you may prefer to omit periods, as in @samp{@@abbr@{Mr@} Stallman}. @code{@@abbr} accepts an optional second argument, intended to be used for the meaning of the abbreviation. If the abbreviation ends with a lowercase letter and a period, and is not at the end of a sentence, and has no second argument, remember to use the @code{@@.} command (@pxref{Not Ending a Sentence}) to get the correct spacing. However, you do not have to use @code{@@.} within the abbreviation itself; Texinfo automatically assumes periods within the abbreivation do not end a sentence. @cindex <abbr> tag In @TeX{} and in the Info output, the first argument is printed as-is; if the second argument is present, it is printed in parentheses after the abbreviation. In HTML and XML, the @code{<abbr>} tag is used; in Docbook, the @code{<abbrev>} tag is used. For instance: @example @@abbr@{Comput. J., Computer Journal@} @end example @noindent produces: @display @abbr{Comput. J., Computer Journal} @end display For abbreviations consisting of all capital letters, you may prefer to use the @code{@@acronym} command instead. See the next section for more on the usage of these two commands. @node acronym @subsection @code{@@acronym}@{@var{acronym}[, @var{meaning}]@} @findex acronym @cindex NASA, as acronym @cindex Acronyms, tagging Use the @code{@@acronym} command for abbreviations written in all capital letters, such as `@acronym{NASA}'. The abbreviation is given as the single argument in braces, as in @samp{@@acronym@{NASA@}}. As a matter of style, or for particular acronyms, you may prefer to use periods, as in @samp{@@acronym@{N.A.S.A.@}}. @code{@@acronym} accepts an optional second argument, intended to be used for the meaning of the acronym. If the acronym is at the end of a sentence, and if there is no second argument, remember to use the @code{@@.} or similar command (@pxref{Ending a Sentence}) to get the correct spacing. @cindex <acronym> tag In @TeX{}, the acronym is printed in slightly smaller font. In the Info output, the argument is printed as-is. In either format, if the second argument is present, it is printed in parentheses after the acronym. In HTML, Docbook, and XML, the @code{<acronym>} tag is used. For instance (since GNU is a recursive acronym, we use @code{@@acronym} recursively): @example @@acronym@{GNU, @@acronym@{GNU@}'s Not Unix@} @end example @noindent produces: @display @acronym{GNU, @acronym{GNU}'s Not Unix} @end display In some circumstances, it is conventional to print family names in all capitals. Don't use @code{@@acronym} for this, since a name is not an acronym. Use @code{@@sc} instead (@pxref{Smallcaps}). @code{@@abbr} and @code{@@acronym} are closely related commands: they both signal to the reader that a shortened form is being used, and possibly give a meaning. When choosing whether to use these two commands, please bear the following in mind. @itemize @minus @item In standard English usage, acronyms are a subset of abbreviations: they include pronounceable words like `@acronym{NATO}', `radar', and `snafu', and some sources also include syllable acronyms like `Usenet', hybrids like `@acronym{SIGGRAPH}', and unpronounceable initialisms like `@acronym{FBI}'. @item In Texinfo, an acronym (but not an abbreviation) should consist only of capital letters and periods, no lowercase. @item In @TeX{}, an acronym (but not an abbreviation) is printed in a slightly smaller font. @item Some browsers place a dotted bottom border under abbreviations but not acronyms. @item It's not essential to use these commands for all abbreviations. Text is perfectly readable without them, and for common abbreviations like `etc.@:', we consider them to be overkill. @end itemize @node indicateurl @subsection @code{@@indicateurl}@{@var{uniform-resource-locator}@} @findex indicateurl @cindex Uniform resource locator, indicating @cindex URL, indicating Use the @code{@@indicateurl} command to indicate a uniform resource locator on the World Wide Web. This is analogous to @code{@@file}, @code{@@var}, etc., and is purely for markup purposes. It does not produce a link you can follow in HTML output (use the @code{@@uref} command for that, @pxref{uref,, @code{@@uref}}). It is useful for url's which do not actually exist. For example: @example For example, the url might be @@indicateurl@{http://example.org/path@}. @end example @noindent which produces: @display For example, the url might be @indicateurl{http://example.org/path}. @end display @node email @subsection @code{@@email}@{@var{email-address}[, @var{displayed-text}]@} @findex email Use the @code{@@email} command to indicate an electronic mail address. It takes one mandatory argument, the address, and one optional argument, the text to display (the default is the address itself). @cindex Mailto link In Info, the address is shown in angle brackets, preceded by the text to display if any. In @TeX{}, the angle brackets are omitted. In HTML output, @code{@@email} produces a @samp{mailto} link that usually brings up a mail composition window. For example: @example Send bug reports to @@email@{bug-texinfo@@@@gnu.org@}, suggestions to the @@email@{bug-texinfo@@@@gnu.org, same place@}. @end example @noindent produces @display Send bug reports to @email{bug-texinfo@@gnu.org}, suggestions to the @email{bug-texinfo@@gnu.org, same place}. @end display @node Emphasis @comment node-name, next, previous, up @section Emphasizing Text @cindex Emphasizing text Usually, Texinfo changes the font to mark words in the text according to what category the words belong to; an example is the @code{@@code} command. Most often, this is the best way to mark words. However, sometimes you will want to emphasize text without indicating a category. Texinfo has two commands to do this. Also, Texinfo has several commands that specify the font in which @TeX{} will typeset text. These commands have no effect on Info and only one of them, the @code{@@r} command, has any regular use.@refill @menu * emph & strong:: How to emphasize text in Texinfo. * Smallcaps:: How to use the small caps font. * Fonts:: Various font commands for printed output. @end menu @node emph & strong @subsection @code{@@emph}@{@var{text}@} and @code{@@strong}@{@var{text}@} @cindex Emphasizing text, font for @findex emph @findex strong The @code{@@emph} and @code{@@strong} commands are for emphasis; @code{@@strong} is stronger. In printed output, @code{@@emph} produces @emph{italics} and @code{@@strong} produces @strong{bold}. For example, @example @group @@strong@{Caution:@} @@samp@{rm * .[^.]*@} removes @@emph@{all@} files in the directory. @end group @end example @noindent produces the following in printed output and HTML: @quotation @strong{Caution}: @samp{rm * .[^.]*} removes @emph{all} files in the directory. @end quotation @noindent and the following in Info: @example *Caution:* `rm * .[^.]*' removes _all_ files in the directory. @end example The @code{@@strong} command is seldom used except to mark what is, in effect, a typographical element, such as the word `Caution' in the preceding example. In the Info output, @code{@@emph} surrounds the text with underscores (@samp{_}), and @code{@@strong} puts asterisks around the text. @quotation Caution Do not use @code{@@strong} with the word @samp{Note}; Info will mistake the combination for a cross reference. (It's usually redundant, anyway.) Use a phrase such as @strong{Please notice} or @strong{Caution} instead, or the optional argument to @code{@@quotation}---@samp{Note} is allowable there. @end quotation @node Smallcaps @subsection @code{@@sc}@{@var{text}@}: The Small Caps Font @cindex Small caps font @findex sc @r{(small caps font)} Use the @samp{@@sc} command to set text in @sc{a small caps font} (where possible). Write the text you want to be in small caps between braces in lower case, like this: @example Richard @@sc@{Stallman@} founded @@acronym@{GNU@}. @end example @noindent This produces: @display Richard @sc{Stallman} founded @acronym{GNU}. @end display As shown here, we recommend using @code{@@acronym} for actual acronyms (@pxref{acronym}), and reserving @code{@@sc} for special cases where you want small caps. The output is not the same (@code{@@acronym} prints in a smaller text font, not the small caps font), but more importantly it describes the actual text more accurately. Family names are one case where small capitals are sometimes desirable, also as shown here. @cindex <small> tag @TeX{} typesets any uppercase letters between the braces of an @code{@@sc} command in full-size capitals; only lowercase letters are printed in the small caps font. In the Info output, the argument to @code{@@sc} is printed in all upper case. In HTML, the argument is uppercased and the output marked with the @code{<small>} tag to reduce the font size. Since it's redundant to mark all-uppercase text with @code{@@sc}, @command{makeinfo} warns about such usage. We recommend using regular mixed case wherever possible. @node Fonts @subsection Fonts for Printing, Not Info @cindex Fonts for printing, not Info Texinfo provides a number of font commands that specify font changes in the printed manual and (where possible) in the HTML output, but have no effect in the Info file. All the commands apply to an argument that follows, surrounded by braces. @table @code @item @@b @findex b @r{(bold font)} @cindex Bold font selects @b{bold} face; @item @@i @findex i @r{(italic font)} @cindex Italic font selects an @i{italic} font; @item @@r @findex r @r{(roman font)} @cindex Roman font @cindex Default font selects a @r{roman} font, which is the usual font in which text is printed. It may or may not be seriffed. @item @@sansserif @findex sansserif @r{(sans serif font)} @cindex Sans serif font selects a @sansserif{sans serif} font; @item @@slanted @findex slanted @r{(slanted font)} @cindex Slanted font @cindex Oblique font rselects a @slanted{slanted} font; @item @@t @findex t @r{(typewriter font)} @cindex Monospace font @cindex Fixed-width font @cindex Typewriter font selects the @t{fixed-width}, typewriter-style font used by @code{@@code}; @end table (The commands with longer names were invented much later than the others, when it did not seem desirable to use very short names for such an infrequently needed feature.) @cindex <lineannotation> Docbook tag Only the @code{@@r} command has much use: in example-like environments, you can use the @code{@@r} command to write comments in the standard roman font instead of the fixed-width font. This looks better in printed output, and produces a @code{<lineannotation>} tag in Docbook output. For example, @example @group @@lisp (+ 2 2) ; @@r@{Add two plus two.@} @@end lisp @end group @end example @noindent produces @lisp (+ 2 2) ; @r{Add two plus two.} @end lisp In general, you should avoid using the other font commands. Some of them are only useful when documenting functionality with specific font effects, such as in \TeX\ and related packages. @node Quotations and Examples @chapter Quotations and Examples Quotations and examples are blocks of text consisting of one or more whole paragraphs that are set off from the bulk of the text and treated differently. They are usually indented in the output. @findex end In Texinfo, you always begin a quotation or example by writing an @@-command at the beginning of a line by itself, and end it by writing an @code{@@end} command that is also at the beginning of a line by itself. For instance, you begin an example by writing @code{@@example} by itself at the beginning of a line and end the example by writing @code{@@end example} on a line by itself, at the beginning of that line, and with only one space between the @code{@@end} and the @code{example}. @menu * Block Enclosing Commands:: Different constructs for different purposes. * quotation:: Writing a quotation. * example:: Writing an example in a fixed-width font. * verbatim:: Writing a verbatim example. * verbatiminclude:: Including a file verbatim. * lisp:: Illustrating Lisp code. * small:: Examples in a smaller font. * display:: Writing an example in the current font. * format:: Writing an example without narrowed margins. * exdent:: Undo indentation on a line. * flushleft & flushright:: Pushing text flush left or flush right. * noindent:: Preventing paragraph indentation. * indent:: Forcing paragraph indentation. * cartouche:: Drawing rounded rectangles around examples. @end menu @node Block Enclosing Commands @section Block Enclosing Commands Here are commands for quotations and examples, explained further in the following sections: @table @code @item @@quotation Indicate text that is quoted. The text is filled, indented (from both margins), and printed in a roman font by default. @item @@example Illustrate code, commands, and the like. The text is printed in a fixed-width font, and indented but not filled. @item @@verbatim Mark a piece of text that is to be printed verbatim; no character substitutions are made and all commands are ignored, until the next @code{@@end verbatim}. The text is printed in a fixed-width font, and not indented or filled. Extra spaces and blank lines are significant, and tabs are expanded. @item @@smallexample Same as @code{@@example}, except that in @TeX{} this command typesets text in a smaller font. @item @@lisp Like @code{@@example}, but specifically for illustrating Lisp code. The text is printed in a fixed-width font, and indented but not filled. @item @@smalllisp Is to @code{@@lisp} as @code{@@smallexample} is to @code{@@example}. @item @@display Display illustrative text. The text is indented but not filled, and no font is selected (so, by default, the font is roman).@refill @item @@smalldisplay Is to @code{@@display} as @code{@@smallexample} is to @code{@@example}. @item @@format Like @code{@@display} (the text is not filled and no font is selected), but the text is not indented. @item @@smallformat Is to @code{@@format} as @code{@@smallexample} is to @code{@@example}. @end table The @code{@@exdent} command is used within the above constructs to undo the indentation of a line. The @code{@@flushleft} and @code{@@flushright} commands are used to line up the left or right margins of unfilled text.@refill The @code{@@noindent} command may be used after one of the above constructs to prevent the following text from being indented as a new paragraph. You can use the @code{@@cartouche} environment around one of the above constructs to highlight the example or quotation by drawing a box with rounded corners around it. @xref{cartouche, , Drawing Cartouches Around Examples}. @node quotation @section @code{@@quotation}: Block quotations @cindex Quotations @findex quotation The text of a quotation is processed normally (regular font, text is filled) except that: @itemize @bullet @item the margins are closer to the center of the page, so the whole of the quotation is indented; @item and the first lines of paragraphs are indented no more than other lines. @end itemize @quotation This is an example of text written between an @code{@@quotation} command and an @code{@@end quotation} command. An @code{@@quotation} command is most often used to indicate text that is excerpted from another (real or hypothetical) printed work. @end quotation Write an @code{@@quotation} command as text on a line by itself. This line will disappear from the output. Mark the end of the quotation with a line beginning with and containing only @code{@@end quotation}. The @code{@@end quotation} line will likewise disappear from the output. @code{@@quotation} takes one optional argument, given on the remainder of the line. This text, if present, is included at the beginning of the quotation in bold or otherwise emphasized, and followed with a @samp{:}. For example: @example @@quotation Note This is a foo. @@end quotation @end example @noindent produces @quotation Note This is a foo. @end quotation If the @code{@@quotation} argument is exactly one of these words: @example Caution Important Note Tip Warning @end example @cindex <note> Docbook tag @cindex <blockquote> HTML tag @noindent then the Docbook output uses corresponding special tags (@code{<note>}, etc.) instead of the default @code{<blockquote>}. HTML output always uses @code{<blockquote>}. @node example @section @code{@@example}: Example Text @cindex Examples, formatting them @cindex Formatting examples @findex example The @code{@@example} environment is used to indicate an example that is not part of the running text, such as computer input or output. Write an @code{@@example} command at the beginning of a line by itself. Mark the end of the example with an @code{@@end example} command, also written at the beginning of a line by itself. An @code{@@example} environment has the following characteristics: @itemize @item Each line in the input file is a line in the output; that is, the source text is not filled as it normally is. @item Extra spaces and blank lines are significant. @item The output is indented. @item The output uses a fixed-width font. @item Texinfo commands @emph{are} expanded; if you want the output to be the input verbatim, use the @code{@@verbatim} environment instead (@pxref{verbatim,,@code{@@verbatim}}). @end itemize For example, @example @@example cp foo @@var@{dest1@}; \ cp foo @@var@{dest2@} @@end example @end example @noindent produces @example cp foo @var{dest1}; \ cp foo @var{dest2} @end example The lines containing @code{@@example} and @code{@@end example} will disappear from the output. To make the output look good, you should put a blank line before the @code{@@example} and another blank line after the @code{@@end example}. Blank lines inside the beginning @code{@@example} and the ending @code{@@end example}, on the other hand, do appear in the output. @quotation Caution Do not use tabs in the lines of an example! (Or anywhere else in Texinfo, except in verbatim environments.) @TeX{} treats tabs as single spaces, and that is not what they look like. In Emacs, you can use @kbd{M-x untabify} to convert tabs in a region to multiple spaces. @end quotation Examples are often, logically speaking, ``in the middle'' of a paragraph, and the text that continues afterwards should not be indented, as in the example above. The @code{@@noindent} command prevents a piece of text from being indented as if it were a new paragraph (@pxref{noindent,,@code{@@noindent}}. If you want to embed code fragments within sentences, instead of displaying them, use the @code{@@code} command or its relatives (@pxref{code,,@code{@@code}}). If you wish to write a ``comment'' on a line of an example in the normal roman font, you can use the @code{@@r} command (@pxref{Fonts}). @node verbatim @section @code{@@verbatim}: Literal Text @findex verbatim @cindex Verbatim environment Use the @code{@@verbatim} environment for printing of text that may contain special characters or commands that should not be interpreted, such as computer input or output (@code{@@example} interprets its text as regular Texinfo commands). This is especially useful for including automatically generated output in a Texinfo manual. Here is an example; the output you see is just the same as the input, with a line @code{@@verbatim} before and a line @code{@@end verbatim} after. @verbatim This is an example of text written in a @verbatim block. No character substitutions are made. All commands are ignored, until `<at>end verbatim'. In the printed manual, the text is typeset in a fixed-width font, and not indented or filled. All spaces and blank lines are significant, including tabs. @end verbatim Write a @code{@@verbatim} command at the beginning of a line by itself. This line will disappear from the output. Mark the end of the verbatim block with a @code{@@end verbatim} command, also written at the beginning of a line by itself. The @code{@@end verbatim} will also disappear from the output. For example: @c oops, got to trick this a bit: can't use @end verbatim inside @verbatim @example @exdent @t{@@verbatim} @exdent @t{@{} @exdent @key{TAB}@t{@@command with strange characters: @@'e} @exdent @t{expand@key{TAB}me} @exdent @t{@}} @exdent @t{@@end verbatim} @end example @noindent produces @verbatim { @command with strange characters: @'e expand me } @end verbatim Since the lines containing @code{@@verbatim} and @code{@@end verbatim} produce no output, typically you should put a blank line before the @code{@@verbatim} and another blank line after the @code{@@end verbatim}. Blank lines between the beginning @code{@@verbatim} and the ending @code{@@end verbatim} will appear in the output. It is not reliable to use @code{@@verbatim} inside other Texinfo constructs. @node verbatiminclude @section @code{@@verbatiminclude} @var{file}: Include a File Verbatim @cindex Verbatim, include file @cindex Including a file verbatim @findex verbatiminclude You can include the exact contents of a file in the document with the @code{@@verbatiminclude} command: @example @@verbatiminclude @var{filename} @end example The contents of @var{filename} is printed in a verbatim environment (@pxref{verbatim,,@code{@@verbatim}}). Generally, the file is printed exactly as it is, with all special characters and white space retained. No indentation is added; if you want indentation, enclose the @code{@@verbatiminclude} within @code{@@example} (@pxref{example,,@code{@@example}}). The name of the file is taken literally, with a single exception: @code{@@value@{@var{var}@}} references are expanded. This makes it possible to reliably include files in other directories in a distribution, for instance: @example @@include @@value@{top_srcdir@}/NEWS @end example @noindent (You still have to get @code{top_srcdir} defined in the first place.) @node lisp @section @code{@@lisp}: Marking a Lisp Example @findex lisp @cindex Lisp example The @code{@@lisp} command is used for Lisp code. It is synonymous with the @code{@@example} command. @lisp This is an example of text written between an @code{@@lisp} command and an @code{@@end lisp} command. @end lisp Use @code{@@lisp} instead of @code{@@example} to preserve information regarding the nature of the example. This is useful, for example, if you write a function that evaluates only and all the Lisp code in a Texinfo file. Then you can use the Texinfo file as a Lisp library.@footnote{It would be straightforward to extend Texinfo to work in a similar fashion for C, Fortran, or other languages.} Mark the end of @code{@@lisp} with @code{@@end lisp} on a line by itself. @node small @section @code{@@small@dots{}} Block Commands @cindex Small examples @cindex Examples in smaller fonts @cindex Lisp examples in smaller fonts @findex smalldisplay @findex smallexample @findex smallformat @findex smalllisp In addition to the regular @code{@@example} and @code{@@lisp} commands, Texinfo has ``small'' example-style commands. These are @code{@@smalldisplay}, @code{@@smallexample}, @code{@@smallformat}, and @code{@@smalllisp}. In Info, the @code{@@small@dots{}} commands are equivalent to their non-small companion commands. In @TeX{}, however, the @code{@@small@dots{}} commands typeset text in a smaller font than the non-small example commands. Consequently, many examples containing long lines fit on a page without needing to be shortened. Mark the end of an @code{@@small@dots{}} block with a corresponding @code{@@end small@dots{}}. For example, pair @code{@@smallexample} with @code{@@end smallexample}. Here is an example of the font used by the @code{@@small@dots{}} commands (in Info, the output will be the same as usual): @smallexample @dots{} to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things. @end smallexample The @code{@@small@dots{}} commands make it easier to prepare manuals without forcing you to edit examples by hand to fit them onto narrower pages. As a general rule, a printed document looks much better if you use only one of (for instance) @code{@@example} or @code{@@smallexample} consistently within a chapter. @node display @section @code{@@display} and @code{@@smalldisplay} @cindex Display formatting @findex display The @code{@@display} command begins a kind of example, where each line of input produces a line of output, and the output is indented. It is thus like the @code{@@example} command except that, in a printed manual, @code{@@display} does not select the fixed-width font. In fact, it does not specify the font at all, so that the text appears in the same font it would have appeared in without the @code{@@display} command. @display This is an example of text written between an @code{@@display} command and an @code{@@end display} command. The @code{@@display} command indents the text, but does not fill it. @end display @findex smalldisplay Texinfo also provides a command @code{@@smalldisplay}, which is like @code{@@display} but uses a smaller font in @code{@@smallbook} format. @xref{small}. The @code{@@table} command (@pxref{table}) does not work inside @code{@@display}. Since @code{@@display} is line-oriented, it doesn't make sense to use them together. If you want to indent a table, try @code{@@quotation} (@pxref{quotation}). @node format @section @code{@@format} and @code{@@smallformat} @findex format The @code{@@format} command is similar to @code{@@example} except that, in the printed manual, @code{@@format} does not select the fixed-width font and does not narrow the margins.@refill @format This is an example of text written between an @code{@@format} command and an @code{@@end format} command. As you can see from this example, the @code{@@format} command does not fill the text. @end format @findex smallformat Texinfo also provides a command @code{@@smallformat}, which is like @code{@@format} but uses a smaller font in @code{@@smallbook} format. @xref{small}. @node exdent @section @code{@@exdent}: Undoing a Line's Indentation @cindex Indentation undoing @findex exdent The @code{@@exdent} command removes any indentation a line might have. The command is written at the beginning of a line and applies only to the text that follows the command that is on the same line. Do not use braces around the text. In a printed manual, the text on an @code{@@exdent} line is printed in the roman font.@refill @code{@@exdent} is usually used within examples. Thus,@refill @example @group @@example This line follows an @@@@example command. @@exdent This line is exdented. This line follows the exdented line. The @@@@end example comes on the next line. @@end group @end group @end example @noindent produces @example @group This line follows an @@example command. @exdent This line is exdented. This line follows the exdented line. The @@end example comes on the next line. @end group @end example In practice, the @code{@@exdent} command is rarely used. Usually, you un-indent text by ending the example and returning the page to its normal width.@refill @node flushleft & flushright @section @code{@@flushleft} and @code{@@flushright} @findex flushleft @findex flushright @cindex Ragged right @cindex Ragged left The @code{@@flushleft} and @code{@@flushright} commands line up the ends of lines on the left and right margins of a page, but do not fill the text. The commands are written on lines of their own, without braces. The @code{@@flushleft} and @code{@@flushright} commands are ended by @code{@@end flushleft} and @code{@@end flushright} commands on lines of their own.@refill @need 1500 For example, @example @group @@flushleft This text is written flushleft. @@end flushleft @end group @end example @noindent produces @quotation @flushleft This text is written flushleft. @end flushleft @end quotation @code{@@flushright} produces the type of indentation often used in the return address of letters. For example, @example @group @@flushright Here is an example of text written flushright. The @@code@{@@flushright@} command right justifies every line but leaves the left end ragged. @@end flushright @end group @end example @noindent produces @flushright Here is an example of text written flushright. The @code{@@flushright} command right justifies every line but leaves the left end ragged. @end flushright @node noindent @section @code{@@noindent}: Omitting Indentation @cindex Omitting indentation @cindex Suppressing indentation @cindex Indentation, omitting @findex noindent An example or other inclusion can break a paragraph into segments. Ordinarily, the formatters indent text that follows an example as a new paragraph. You can prevent this on a case-by-case basis by writing @code{@@noindent} at the beginning of a line, preceding the continuation text. You can also disable indentation for all paragraphs globally with @code{@@paragraphindent} (@pxref{paragraphindent, Paragraph Indenting}). It is best to write @code{@@noindent} on a line by itself, since in most environments, spaces following the command will not be ignored. It's ok to use it at the beginning of a line, with text following, outside of any environment. @need 1500 For example: @example @group @@example This is an example @@end example @@noindent This line is not indented. As you can see, the beginning of the line is fully flush left with the line that follows after it. (This whole example is between @@code@{@@@@display@} and @@code@{@@@@end display@}.) @end group @end example @noindent produces: @display @example This is an example @end example @noindent This line is not indented. As you can see, the beginning of the line is fully flush left with the line that follows after it. (This whole example is between @code{@@display} and @code{@@end display}.) @end display To adjust the number of blank lines properly in the Info file output, remember that the line containing @code{@@noindent} does not generate a blank line, and neither does the @code{@@end example} line. In the Texinfo source file for this manual, each line that says `produces' is preceded by @code{@@noindent}. Do not put braces after an @code{@@noindent} command; they are not necessary, since @code{@@noindent} is a command used outside of paragraphs (@pxref{Command Syntax}). @node indent @section @code{@@indent}: Forcing Indentation @cindex Forcing indentation @cindex Inserting indentation @cindex Indentation, forcing @findex indent @indent To complement the @code{@@noindent} command (see the previous section), Texinfo provides the @code{@@indent} command that forces a paragraph to be indented. This paragraph, for instance, is indented using an @code{@@indent} command. The first paragraph of a section is the most likely place to use @code{@@indent}, to override the normal behavior of no indentation there (@pxref{paragraphindent}). It is best to write @code{@@indent} on a line by itself, since in most environments, spaces following the command will not be ignored. The @code{@@indent} line will not generate a blank line in the Info output within an environment. However, it is ok to use it at the beginning of a line, with text following, outside of any environment. Do not put braces after an @code{@@indent} command; they are not necessary, since @code{@@indent} is a command used outside of paragraphs (@pxref{Command Syntax}). @node cartouche @section @code{@@cartouche}: Rounded Rectangles Around Examples @findex cartouche @cindex Box with rounded corners @cindex Rounded rectangles, around examples In a printed manual, the @code{@@cartouche} command draws a box with rounded corners around its contents. In HTML, a normal rectangle is drawn (that's the best HTML can do). @code{@@cartouche} has no effect in Info output. You can use this command to further highlight an example or quotation. For instance, you could write a manual in which one type of example is surrounded by a cartouche for emphasis. For example, @example @@cartouche @@example % pwd /usr/local/share/emacs @@end example @@end cartouche @end example @noindent surrounds the two-line example with a box with rounded corners, in the printed manual. The output from the example looks like this (if you're reading this in Info, you'll see the @code{@@cartouche} had no effect): @cartouche @example % pwd /usr/local/info @end example @end cartouche For proper output in HTML, it's necessary to put the @code{@@cartouche} around the @code{@@example}, and not the other way around. This limitation of @command{makeinfo} may be removed one day. @code{@@cartouche} also implies @code{@@group} (@pxref{group}). @node Lists and Tables @chapter Lists and Tables @cindex Making lists and tables @cindex Lists and tables, making @cindex Tables and lists, making Texinfo has several ways of making lists and tables. Lists can be bulleted or numbered; two-column tables can highlight the items in the first column; multi-column tables are also supported. @menu * Introducing Lists:: Texinfo formats lists for you. * itemize:: How to construct a simple list. * enumerate:: How to construct a numbered list. * Two-column Tables:: How to construct a two-column table. * Multi-column Tables:: How to construct generalized tables. @end menu @node Introducing Lists @section Introducing Lists Texinfo automatically indents the text in lists or tables, and numbers an enumerated list. This last feature is useful if you modify the list, since you do not need to renumber it yourself.@refill Numbered lists and tables begin with the appropriate @@-command at the beginning of a line, and end with the corresponding @code{@@end} command on a line by itself. The table and itemized-list commands also require that you write formatting information on the same line as the beginning @@-command.@refill Begin an enumerated list, for example, with an @code{@@enumerate} command and end the list with an @code{@@end enumerate} command. Begin an itemized list with an @code{@@itemize} command, followed on the same line by a formatting command such as @code{@@bullet}, and end the list with an @code{@@end itemize} command.@refill @findex end Precede each element of a list with an @code{@@item} or @code{@@itemx} command.@refill @sp 1 @noindent Here is an itemized list of the different kinds of table and lists:@refill @itemize @bullet @item Itemized lists with and without bullets. @item Enumerated lists, using numbers or letters. @item Two-column tables with highlighting. @end itemize @sp 1 @noindent Here is an enumerated list with the same items:@refill @enumerate @item Itemized lists with and without bullets. @item Enumerated lists, using numbers or letters. @item Two-column tables with highlighting. @end enumerate @sp 1 @noindent And here is a two-column table with the same items and their @w{@@-commands}:@refill @table @code @item @@itemize Itemized lists with and without bullets. @item @@enumerate Enumerated lists, using numbers or letters. @item @@table @itemx @@ftable @itemx @@vtable Two-column tables, optionally with indexing. @end table @node itemize @section @code{@@itemize}: Making an Itemized List @cindex Itemization @findex itemize The @code{@@itemize} command produces sequences of indented paragraphs, with a bullet or other mark inside the left margin at the beginning of each paragraph for which such a mark is desired.@refill @cindex @code{@@w}, for blank items Begin an itemized list by writing @code{@@itemize} at the beginning of a line. Follow the command, on the same line, with a character or a Texinfo command that generates a mark. Usually, you will write @code{@@bullet} after @code{@@itemize}, but you can use @code{@@minus}, or any command or character that results in a single character in the Info file. If you don't want any mark at all, use @code{@@w}. (When you write the mark command such as @code{@@bullet} after an @code{@@itemize} command, you may omit the @samp{@{@}}.) If you don't specify a mark command, the default is @code{@@bullet}. Write the text of the indented paragraphs themselves after the @code{@@itemize}, up to another line that says @code{@@end itemize}.@refill @findex item At the beginning of each paragraph for which a mark in the margin is desired, write a line that starts with @code{@@item}. It is ok to have text following the @code{@@item}. Usually, you should put a blank line before an @code{@@item}. This puts a blank line in the Info file. (@TeX{} inserts the proper interline whitespace in either case.) Except when the entries are very brief, these blank lines make the list look better.@refill Here is an example of the use of @code{@@itemize}, followed by the output it produces. @code{@@bullet} produces an @samp{*} in Info and a round dot in @TeX{}. @example @group @@itemize @@bullet @@item Some text for foo. @@item Some text for bar. @@end itemize @end group @end example @noindent This produces: @quotation @itemize @bullet @item Some text for foo. @item Some text for bar. @end itemize @end quotation Itemized lists may be embedded within other itemized lists. Here is a list marked with dashes embedded in a list marked with bullets:@refill @example @group @@itemize @@bullet @@item First item. @@itemize @@minus @@item Inner item. @@item Second inner item. @@end itemize @@item Second outer item. @@end itemize @end group @end example @noindent This produces: @quotation @itemize @bullet @item First item. @itemize @minus @item Inner item. @item Second inner item. @end itemize @item Second outer item. @end itemize @end quotation @node enumerate @section @code{@@enumerate}: Making a Numbered or Lettered List @cindex Enumeration @findex enumerate @code{@@enumerate} is like @code{@@itemize} (@pxref{itemize,, @code{@@itemize}}), except that the labels on the items are successive integers or letters instead of bullets. Write the @code{@@enumerate} command at the beginning of a line. The command does not require an argument, but accepts either a number or a letter as an option. Without an argument, @code{@@enumerate} starts the list with the number @samp{1}. With a numeric argument, such as @samp{3}, the command starts the list with that number. With an upper or lower case letter, such as @samp{a} or @samp{A}, the command starts the list with that letter. Write the text of the enumerated list in the same way as an itemized list: write a line starting with @code{@@item} at the beginning of each paragraph that you want enumerated. It is ok to have text following the @code{@@item}. You should put a blank line between entries in the list. This generally makes it easier to read the Info file. @need 1500 Here is an example of @code{@@enumerate} without an argument: @example @group @@enumerate @@item Underlying causes. @@item Proximate causes. @@end enumerate @end group @end example @noindent This produces: @enumerate @item Underlying causes. @item Proximate causes. @end enumerate @sp 1 Here is an example with an argument of @kbd{3}:@refill @sp 1 @example @group @@enumerate 3 @@item Predisposing causes. @@item Precipitating causes. @@item Perpetuating causes. @@end enumerate @end group @end example @noindent This produces: @enumerate 3 @item Predisposing causes. @item Precipitating causes. @item Perpetuating causes. @end enumerate @sp 1 Here is a brief summary of the alternatives. The summary is constructed using @code{@@enumerate} with an argument of @kbd{a}.@refill @sp 1 @enumerate a @item @code{@@enumerate} Without an argument, produce a numbered list, starting with the number 1.@refill @item @code{@@enumerate @var{positive-integer}} With a (positive) numeric argument, start a numbered list with that number. You can use this to continue a list that you interrupted with other text.@refill @item @code{@@enumerate @var{upper-case-letter}} With an upper case letter as argument, start a list in which each item is marked by a letter, beginning with that upper case letter.@refill @item @code{@@enumerate @var{lower-case-letter}} With a lower case letter as argument, start a list in which each item is marked by a letter, beginning with that lower case letter.@refill @end enumerate You can also nest enumerated lists, as in an outline.@refill @node Two-column Tables @section Making a Two-column Table @cindex Tables, making two-column @findex table @code{@@table} is similar to @code{@@itemize} (@pxref{itemize,, @code{@@itemize}}), but allows you to specify a name or heading line for each item. The @code{@@table} command is used to produce two-column tables, and is especially useful for glossaries, explanatory exhibits, and command-line option summaries. @menu * table:: How to construct a two-column table. * ftable vtable:: Automatic indexing for two-column tables. * itemx:: How to put more entries in the first column. @end menu @node table @subsection Using the @code{@@table} Command @cindex Definition lists, typesetting Use the @code{@@table} command to produce two-column tables. It is usually listed for ``definition lists'' of various sorts, where you have a list of terms and a brief text with each one. Write the @code{@@table} command at the beginning of a line, after a blank line, and follow it on the same line with an argument that is a Texinfo ``indicating'' command such as @code{@@code}, @code{@@samp}, @code{@@var}, @code{@@option}, or @code{@@kbd} (@pxref{Indicating}). This command will be applied to the text that goes into the first column of each item and thus determines how it will be highlighted. For example, @code{@@table @@code} will cause the text in the first column to be output as if it @code{@@code} command. @findex asis You may also use the @code{@@asis} command as an argument to @code{@@table}. @code{@@asis} is a command that does nothing; if you use this command after @code{@@table}, the first column entries are output without added highlighting (``as is''). The @code{@@table} command works with other commands besides those explicitly mentioned here. However, you can only use commands that normally take arguments in braces. (In this case, however, you use the command name without an argument, because the subsequent @code{@@item}'s will supply the argument.) @findex item Begin each table entry with an @code{@@item} command at the beginning of a line. Write the first column text on the same line as the @code{@@item} command. Write the second column text on the line following the @code{@@item} line and on subsequent lines. (You do not need to type anything for an empty second column entry.) You may write as many lines of supporting text as you wish, even several paragraphs. But only the text on the same line as the @code{@@item} will be placed in the first column (including any footnotes). Normally, you should put a blank line before an @code{@@item} line. This puts a blank line in the Info file. Except when the entries are very brief, a blank line looks better. End the table with a line consisting of @code{@@end table}, followed by a blank line. @TeX{} will always start a new paragraph after the table, so the blank line is needed for the Info output to be analogous. @need 1500 The following table, for example, highlights the text in the first column with an @code{@@samp} command: @example @group @@table @@samp @@item foo This is the text for @@samp@{foo@}. @@item bar Text for @@samp@{bar@}. @@end table @end group @end example @noindent This produces: @table @samp @item foo This is the text for @samp{foo}. @item bar Text for @samp{bar}. @end table If you want to list two or more named items with a single block of text, use the @code{@@itemx} command. (@xref{itemx,,@code{@@itemx}}.) @node ftable vtable @subsection @code{@@ftable} and @code{@@vtable} @cindex Tables with indexes @cindex Indexing table entries automatically @findex ftable @findex vtable The @code{@@ftable} and @code{@@vtable} commands are the same as the @code{@@table} command except that @code{@@ftable} automatically enters each of the items in the first column of the table into the index of functions and @code{@@vtable} automatically enters each of the items in the first column of the table into the index of variables. This simplifies the task of creating indices. Only the items on the same line as the @code{@@item} commands are indexed, and they are indexed in exactly the form that they appear on that line. @xref{Indices}, for more information about indices.@refill Begin a two-column table using @code{@@ftable} or @code{@@vtable} by writing the @@-command at the beginning of a line, followed on the same line by an argument that is a Texinfo command such as @code{@@code}, exactly as you would for an @code{@@table} command; and end the table with an @code{@@end ftable} or @code{@@end vtable} command on a line by itself. See the example for @code{@@table} in the previous section. @node itemx @subsection @code{@@itemx} @cindex Two named items for @code{@@table} @findex itemx Use the @code{@@itemx} command inside a table when you have two or more first column entries for the same item, each of which should appear on a line of its own. Use @code{@@item} for the first entry, and @code{@@itemx} for all subsequent entries; @code{@@itemx} must always follow an @code{@@item} command, with no blank line intervening. The @code{@@itemx} command works exactly like @code{@@item} except that it does not generate extra vertical space above the first column text. If you have multiple consecutive @code{@@itemx} commands, do not insert any blank lines between them. For example, @example @group @@table @@code @@item upcase @@itemx downcase These two functions accept a character or a string as argument, and return the corresponding upper case (lower case) character or string. @@end table @end group @end example @noindent This produces: @table @code @item upcase @itemx downcase These two functions accept a character or a string as argument, and return the corresponding upper case (lower case) character or string.@refill @end table @noindent (Note also that this example illustrates multi-line supporting text in a two-column table.)@refill @node Multi-column Tables @section @code{@@multitable}: Multi-column Tables @cindex Tables, making multi-column @findex multitable @code{@@multitable} allows you to construct tables with any number of columns, with each column having any width you like. You define the column widths on the @code{@@multitable} line itself, and write each row of the actual table following an @code{@@item} command, with columns separated by an @code{@@tab} command. Finally, @code{@@end multitable} completes the table. Details in the sections below. @menu * Multitable Column Widths:: Defining multitable column widths. * Multitable Rows:: Defining multitable rows, with examples. @end menu @node Multitable Column Widths @subsection Multitable Column Widths @cindex Multitable column widths @cindex Column widths, defining for multitables @cindex Widths, defining multitable column You can define the column widths for a multitable in two ways: as fractions of the line length; or with a prototype row. Mixing the two methods is not supported. In either case, the widths are defined entirely on the same line as the @code{@@multitable} command. @enumerate @item @findex columnfractions @cindex Line length, column widths as fraction of To specify column widths as fractions of the line length, write @code{@@columnfractions} and the decimal numbers (presumably less than 1; a leading zero is allowed and ignored) after the @code{@@multitable} command, as in: @example @@multitable @@columnfractions .33 .33 .33 @end example The fractions need not add up exactly to 1.0, as these do not. This allows you to produce tables that do not need the full line length. @item @cindex Prototype row, column widths defined by To specify a prototype row, write the longest entry for each column enclosed in braces after the @code{@@multitable} command. For example: @example @@multitable @{some text for column one@} @{for column two@} @end example @noindent The first column will then have the width of the typeset `some text for column one', and the second column the width of `for column two'. The prototype entries need not appear in the table itself. Although we used simple text in this example, the prototype entries can contain Texinfo commands; markup commands such as @code{@@code} are particularly likely to be useful. @end enumerate @node Multitable Rows @subsection Multitable Rows @cindex Multitable rows @cindex Rows, of a multitable @findex item @findex tab After the @code{@@multitable} command defining the column widths (see the previous section), you begin each row in the body of a multitable with @code{@@item}, and separate the column entries with @code{@@tab}. Line breaks are not special within the table body, and you may break input lines in your source file as necessary. @findex headitem @cindex Heading row, in table @cindex <thead> HTML tag You can also use @code{@@headitem} instead of @code{@@item} to produce a @dfn{heading row}. The @TeX{} output for such a row is in bold, and the HTML, XML, and Docbook output uses the @code{<thead>} tag. Here is a complete example of a multi-column table (the text is from @cite{The GNU Emacs Manual}, @pxref{Split Window,, Splitting Windows, emacs, The GNU Emacs Manual}): @example @@multitable @@columnfractions .15 .45 .4 @@headitem Key @@tab Command @@tab Description @@item C-x 2 @@tab @@code@{split-window-vertically@} @@tab Split the selected window into two windows, with one above the other. @@item C-x 3 @@tab @@code@{split-window-horizontally@} @@tab Split the selected window into two windows positioned side by side. @@item C-Mouse-2 @@tab @@tab In the mode line or scroll bar of a window, split that window. @@end multitable @end example @noindent produces: @multitable @columnfractions .15 .45 .4 @headitem Key @tab Command @tab Description @item C-x 2 @tab @code{split-window-vertically} @tab Split the selected window into two windows, with one above the other. @item C-x 3 @tab @code{split-window-horizontally} @tab Split the selected window into two windows positioned side by side. @item C-Mouse-2 @tab @tab In the mode line or scroll bar of a window, split that window. @end multitable @node Special Displays @chapter Special Displays @cindex Special displays The commands in this chapter allow you to write text that is specially displayed (output format permitting), outside of the normal document flow. One set of such commands is for creating ``floats'', that is, figures, tables, and the like, set off from the main text, possibly numbered, captioned, and/or referred to from elsewhere in the document. Images are often included in these displays. Another group of commands is for creating footnotes in Texinfo. @menu * Floats:: Figures, tables, and the like. * Images:: Including graphics and images. * Footnotes:: Writing footnotes. @end menu @node Floats @section Floats @cindex Floats, in general A @dfn{float} is a display which is set off from the main text. It is typically labelled as being a ``Figure'', ``Table'', ``Example'', or some similar type. @cindex Floating, not yet implemented A float is so-named because, in principle, it can be moved to the bottom or top of the current page, or to a following page, in the printed output. (Floating does not make sense in other output formats.) In the present version of Texinfo, however, this floating is unfortunately not yet implemented. Instead, the floating material is simply output at the current location, more or less as if it were an @code{@@group} (@pxref{group,,@code{@@group}}). @menu * float:: Producing floating material. * caption shortcaption:: Specifying descriptions for floats. * listoffloats:: A table of contents for floats. @end menu @node float @subsection @code{@@float} [@var{type}][,@var{label}]: Floating material @findex float @cindex Float environment To produce floating material, enclose the material you want to be displayed separate between @code{@@float} and @code{@@end float} commands, on lines by themselves. Floating material uses @code{@@image} to display an already-existing graphic (@pxref{Images}), or @code{@@multitable} to display a table (@pxref{Multi-column Tables}). However, the contents of the float can be anything. Here's an example with simple text: @example @@float Figure,fig:ex1 This is an example float. @@end float @end example @noindent And the output: @float Figure,fig:ex1 This is an example float. @end float As shown in the example, @code{@@float} takes two arguments (separated by a comma), @var{type} and @var{label}. Both are optional. @table @var @item type Specifies the sort of float this is; typically a word such as ``Figure'', ``Table'', etc. If not given, and @var{label} is, any cross-referencing will simply use a bare number. @item label Specifies a cross-reference label for this float. If given, this float is automatically given a number, and will appear in any @code{@@listofloats} output (@pxref{listoffloats}). Cross-references to @var{label} are allowed. @cindex Floats, making unnumbered @cindex Unnumbered float, creating On the other hand, if @var{label} is not given, then the float will not be numbered and consequently will not appear in the @code{@@listoffloats} output or be cross-referenceable. @end table @noindent Normally, you specify both @var{type} and @var{label}, to get a labeled and numbered float. @cindex Floats, numbering of @cindex Numbering of floats In Texinfo, all floats are numbered the same way: with the chapter number (or appendix letter), a period, and the float number, which simply counts 1, 2, 3, @dots{}, and is reset at each chapter. Each float type is counted independently. Floats within an @code{@@unnumbered} are numbered, or outside of any chapter, are simply numbered consecutively from 1. These numbering conventions are not, at present, changeable. @node caption shortcaption @subsection @code{@@caption} & @code{@@shortcaption} @findex caption @findex shortcaption @cindex Captions, for floats @cindex Short captions, for lists of floats You may write an @code{@@caption} anywhere within a @code{@@float} environment, to define a caption for the float. It is not allowed in any other context. @code{@@caption} takes a single argument, enclosed in braces. Here's an example: @example @@float An example float, with caption. @@caption@{Caption for example float.@} @@end float @end example @noindent The output is: @float An example float, with caption. @caption{Caption for example float.} @end float @code{@@caption} can appear anywhere within the float; it is not processed until the @code{@@end float}. The caption text is usually a sentence or two, but may consist of several paragraphs if necessary. In the output, the caption always appears below the float; this is not currently changeable. It is preceded by the float type and/or number, as specified to the @code{@@float} command (see the previous section). The @code{@@shortcaption} command likewise may be used only within @code{@@float}, and takes a single argument in braces. The short caption text is used instead of the caption text in a list of floats (see the next section). Thus, you can write a long caption for the main document, and a short title to appear in the list of floats. For example: @example @@float ... as above ... @@shortcaption@{Text for list of floats.@} @@end float @end example The text for @code{@@caption} and @code{@@shortcaption} may not contain comments (@code{@@c}), verbatim text (@code{@@verb}), environments such as @code{@@example}, or other complex constructs. @node listoffloats @subsection @code{@@listoffloats}: Tables of contents for floats @findex listoffloats @cindex List of floats @cindex Floats, list of @cindex Table of contents, for floats You can write a @code{@@listoffloats} command to generate a list of floats for a given float type (@pxref{float}), analogous to the document's overall table of contents. Typically, it is written in its own @code{@@unnumbered} node to provide a heading and structure, rather like @code{@@printindex} (@pxref{Printing Indices & Menus}). @code{@@listoffloats} takes one optional argument, the float type. Here's an example: @example @@node List of Figures @@unnumbered List of Figures @@listoffloats Figure @end example @noindent And the output from @code{@@listoffloats}: @display @listoffloats Figure @end display Without any argument, @code{@@listoffloats} generates a list of floats for which no float type was specified, i.e., no first argument to the @code{@@float} command (@pxref{float}). Each line in the list of floats contains the float type (if any), the float number, and the caption, if any---the @code{@@shortcaption} argument, if it was specified, else the @code{@@caption} argument. In Info, the result is a menu where each float can be selected. In HTML, each line is a link to the float. In printed output, the page number is included. Unnumbered floats (those without cross-reference labels) are omitted from the list of floats. @node Images @section Inserting Images @cindex Images, inserting @cindex Pictures, inserting @findex image You can insert an image given in an external file with the @code{@@image} command. Although images can be used anywhere, including the middle of a paragraph, we describe them in this chapter since they are most often part of a displayed figure or example. @menu * Image Syntax:: * Image Scaling:: @end menu @node Image Syntax @subsection Image Syntax Here is the basic synopsis of the @code{@@image} command: @example @@image@{@var{filename}@r{[,} @var{width}@r{[,} @var{height}@r{[,} @var{alttext}@r{[, }@var{extension}@r{]]]]}@} @end example @cindex Formats for images @cindex Image formats The @var{filename} argument is mandatory, and must not have an extension, because the different processors support different formats: @itemize @bullet @item @TeX{} reads the file @file{@var{filename}.eps} (Encapsulated PostScript format). @item @pindex pdftex@r{, and images} PDF@TeX{} reads @file{@var{filename}.pdf} (Adobe's Portable Document Format). @item @code{makeinfo} includes @file{@var{filename}.txt} verbatim for Info output (more or less as if it was an @code{@@example}). @item @code{makeinfo} uses the optional fifth argument @var{extension} to @code{@@image} for the filename extension, if it is specified. For example: @pindex XPM image format @example @@image@{foo,,,,.xpm@} @end example @noindent will cause @code{makeinfo} to look for @file{foo.xpm} before any others. @end itemize The @var{width} and @var{height} arguments are described in the next section. For @TeX{} output, if an image is the first thing in a paragraph, for example if you want two images side-by-side, you must precede it with @code{@@noindent} (@pxref{noindent,,@code{@@noindent}}). Otherwise it will be displayed on a line by itself. If you want it centered, use @code{@@center} (@pxref{titlefont center sp,,@code{@@titlefont @@center @@sp}}). @cindex Alt attribute for images @cindex Images, alternate text for When producing html, @code{makeinfo} sets the @dfn{alt attribute} for inline images to the optional @var{alttext} (fourth) argument to @code{@@image}, if supplied. If not supplied, @code{makeinfo} uses the full file name of the image being displayed. If you want an empty @code{alt} string, use @code{@@-}. The @var{alttext} is taken as Texinfo text, so special characters such as @samp{"} and @samp{<} and @samp{&} are escaped in the HTML and XML output. @cindex GIF images, unsupported due to patents @cindex PNG image format @cindex JPG image format If you do not supply the optional @var{extension} (fifth) argument, @code{makeinfo} first tries @file{@var{filename}.png}; if that does not exist, it tries @file{@var{filename}.jpg}. If that does not exist either, it complains. (We cannot support GIF format directly due to software patents.) In Info output, @code{makeinfo} writes a reference to the binary image file (trying @var{filename} suffixed with @file{@var{extension}}, @file{@var{.extension}}, @file{.png}, or @file{.jpg}, in that order) if one exists. It also literally includes the @file{.txt} file if one exists. This way, Info readers which can display images (such as the Emacs Info browser, running under X) can do so, whereas Info readers which can only use text (such as the standalone Info reader) can display the textual version. The implementation of this is to put the following construct into the Info output: @example ^@@^H[image src="@var{binaryfile}" text="@var{txtfile}" alt="@var{alttext} ... ^@@^H] @end example @noindent where @samp{^@@} and @samp{^H} stand for the actual null and backspace control characters. If one of the files is not present, the corresponding argument is omitted. The reason for mentioning this here is that older Info browsers (this feature was introduced in Texinfo version 4.6) will display the above literally, which, although not pretty, should not be harmful. @node Image Scaling @subsection Image Scaling @cindex Images, scaling @cindex Scaling images @cindex Width of images @cindex Height of images @cindex Aspect ratio of images @cindex Distorting images The optional @var{width} and @var{height} arguments to the @code{@@image} command (see the previous section) specify the size to scale the image to. They are ignored for Info output. If neither is specified, the image is presented in its natural size (given in the file); if only one is specified, the other is scaled proportionately; and if both are specified, both are respected, thus possibly distorting the original image by changing its aspect ratio. @cindex Dimensions and image sizes The @var{width} and @var{height} may be specified using any valid @TeX{} dimension, namely: @table @asis @item pt @cindex Points (dimension) point (72.27pt = 1in) @item pc @cindex Picas pica (1pc = 12pt) @item bp @cindex Big points big point (72bp = 1in) @item in @cindex Inches inch @item cm @cindex Centimeters centimeter (2.54cm = 1in) @item mm @cindex Millimeters millimeter (10mm = 1cm) @item dd @cindex Did@^ot points did@^ot point (1157dd = 1238pt) @item cc @cindex Ciceros cicero (1cc = 12dd) @item sp @cindex Scaled points scaled point (65536sp = 1pt) @end table @pindex ridt.eps For example, the following will scale a file @file{ridt.eps} to one inch vertically, with the width scaled proportionately: @example @@image@{ridt,,1in@} @end example @pindex epsf.tex For @code{@@image} to work with @TeX{}, the file @file{epsf.tex} must be installed somewhere that @TeX{} can find it. (The standard location is @file{@var{texmf}/tex/generic/dvips/epsf.tex}, where @var{texmf} is a root of your @TeX{} directory tree.) This file is included in the Texinfo distribution and is also available from @uref{ftp://tug.org/tex/epsf.tex}, among other places. @code{@@image} can be used within a line as well as for displayed figures. Therefore, if you intend it to be displayed, be sure to leave a blank line before the command, or the output will run into the preceding text. Image scaling is presently implemented only in @TeX{}, not in HTML or any other sort of output. @node Footnotes @section Footnotes @cindex Footnotes @findex footnote A @dfn{footnote} is for a reference that documents or elucidates the primary text.@footnote{A footnote should complement or expand upon the primary text, but a reader should not need to read a footnote to understand the primary text. For a thorough discussion of footnotes, see @cite{The Chicago Manual of Style}, which is published by the University of Chicago Press.} Footnotes are distracting; use them sparingly, if at all. Standard bibliographical references are better placed in a bibliography at the end of a document than in footnotes throughout. @menu * Footnote Commands:: How to write a footnote in Texinfo. * Footnote Styles:: Controlling how footnotes appear in Info. @end menu @node Footnote Commands @subsection Footnote Commands In Texinfo, footnotes are created with the @code{@@footnote} command. This command is followed immediately by a left brace, then by the text of the footnote, and then by a terminating right brace. Footnotes may be of any length (they will be broken across pages if necessary), but are usually short. The template is: @example ordinary text@@footnote@{@var{text of footnote}@} @end example As shown here, the @code{@@footnote} command should come right after the text being footnoted, with no intervening space; otherwise, the footnote marker might end up starting a line. For example, this clause is followed by a sample footnote@footnote{Here is the sample footnote.}; in the Texinfo source, it looks like this: @example @dots{}a sample footnote@@footnote@{Here is the sample footnote.@}; in the Texinfo source@dots{} @end example As you can see, the source includes two punctuation marks next to each other; in this case, @samp{.@};} is the sequence. This is normal (the first ends the footnote and the second belongs to the sentence being footnoted), so don't worry that it looks odd. In a printed manual or book, the reference mark for a footnote is a small, superscripted number; the text of the footnote appears at the bottom of the page, below a horizontal line. In Info, the reference mark for a footnote is a pair of parentheses with the footnote number between them, like this: @samp{(1)}. The reference mark is followed by a cross-reference link to the footnote's text. In the HTML output, footnote references are marked with a small, superscripted number which is rendered as a hypertext link to the footnote text. By the way, footnotes in the argument of an @code{@@item} command for a @code{@@table} must be on the same line as the @code{@@item} (as usual). @xref{Two-column Tables}. @node Footnote Styles @subsection Footnote Styles Info has two footnote styles, which determine where the text of the footnote is located: @itemize @bullet @cindex @samp{@r{End}} node footnote style @item In the `End' node style, all the footnotes for a single node are placed at the end of that node. The footnotes are separated from the rest of the node by a line of dashes with the word @samp{Footnotes} within it. Each footnote begins with an @samp{(@var{n})} reference mark. @need 700 @noindent Here is an example of a single footnote in the end of node style:@refill @example @group --------- Footnotes --------- (1) Here is a sample footnote. @end group @end example @cindex @samp{@r{Separate}} footnote style @item In the `Separate' node style, all the footnotes for a single node are placed in an automatically constructed node of their own. In this style, a ``footnote reference'' follows each @samp{(@var{n})} reference mark in the body of the node. The footnote reference is actually a cross reference which you use to reach the footnote node. The name of the node with the footnotes is constructed by appending @w{@samp{-Footnotes}} to the name of the node that contains the footnotes. (Consequently, the footnotes' node for the @file{Footnotes} node is @w{@file{Footnotes-Footnotes}}!) The footnotes' node has an `Up' node pointer that leads back to its parent node. @noindent Here is how the first footnote in this manual looks after being formatted for Info in the separate node style: @smallexample @group File: texinfo.info Node: Overview-Footnotes, Up: Overview (1) The first syllable of "Texinfo" is pronounced like "speck", not "hex". @dots{} @end group @end smallexample @end itemize Unless your document has long and important footnotes (as in, say, Gibbon's @cite{Decline and Fall @dots{}}), we recommend the @samp{end} style, as it is simpler for readers to follow. @findex footnotestyle Use the @code{@@footnotestyle} command to specify an Info file's footnote style. Write this command at the beginning of a line followed by an argument, either @samp{end} for the end node style or @samp{separate} for the separate node style. @need 700 For example, @example @@footnotestyle end @end example @noindent or @example @@footnotestyle separate @end example Write an @code{@@footnotestyle} command before or shortly after the end-of-header line at the beginning of a Texinfo file. (If you include the @code{@@footnotestyle} command between the start-of-header and end-of-header lines, the region formatting commands will format footnotes as specified.)@refill If you do not specify a footnote style, the formatting commands use their default style. Currently, @code{texinfo-format-buffer} and @code{texinfo-format-region} use the `separate' style and @code{makeinfo} uses the `end' style. @node Indices @chapter Indices @cindex Indices Using Texinfo, you can generate indices without having to sort and collate entries manually. In an index, the entries are listed in alphabetical order, together with information on how to find the discussion of each entry. In a printed manual, this information consists of page numbers. In an Info file, this information is a menu entry leading to the first node referenced. Texinfo provides several predefined kinds of index: an index for functions, an index for variables, an index for concepts, and so on. You can combine indices or use them for other than their canonical purpose. Lastly, you can define your own new indices. @xref{Printing Indices & Menus}, for information on how to print indices. @menu * Index Entries:: Choose different words for index entries. * Predefined Indices:: Use different indices for different kinds of entries. * Indexing Commands:: How to make an index entry. * Combining Indices:: How to combine indices. * New Indices:: How to define your own indices. @end menu @node Index Entries @section Making Index Entries @cindex Index entries, making @cindex Entries, making index When you are making index entries, it is good practice to think of the different ways people may look for something. Different people @emph{do not} think of the same words when they look something up. A helpful index will have items indexed under all the different words that people may use. For example, one reader may think it obvious that the two-letter names for indices should be listed under ``Indices, two-letter names'', since the word ``Index'' is the general concept. But another reader may remember the specific concept of two-letter names and search for the entry listed as ``Two letter names for indices''. A good index will have both entries and will help both readers.@refill Like typesetting, the construction of an index is a highly skilled, professional art, the subtleties of which are not appreciated until you need to do it yourself.@refill @xref{Printing Indices & Menus}, for information about printing an index at the end of a book or creating an index menu in an Info file.@refill @node Predefined Indices @section Predefined Indices Texinfo provides six predefined indices. Here are their nominal meanings, abbreviations, and the corresponding index entry commands: @table @samp @item cp @cindex @code{cp} (concept) index (@code{@@cindex}) concept index, for general concepts. @item fn @cindex @code{fn} (function) index (@code{@@findex}) function index, for function and function-like names (such as entry points of libraries). @item ky @cindex @code{ky} (keystroke) index (@code{@@kindex}) keystroke index, for keyboard commands. @item pg @cindex @code{pg} (program) index (@code{@@pindex}) program index, for names of programs. @item tp @cindex @code{tp} (data type) index (@code{@@tindex}) data type index, for type names (such as structures defined in header files). @item vr @cindex @code{vr} (variable) index (@code{@@vindex}) variable index, for variable names (such as global variables of libraries). @end table @noindent Not every manual needs all of these, and most manuals use only two or three at most. The present manual, for example, has two indices: a concept index and an @@-command index (that is actually the function index but is called a command index in the chapter heading). You are not required to use the predefined indices strictly for their canonical purposes. For example, suppose you wish to index some C preprocessor macros. You could put them in the function index along with actual functions, just by writing @code{@@findex} commands for them; then, when you print the ``Function Index'' as an unnumbered chapter, you could give it the title `Function and Macro Index' and all will be consistent for the reader. On the other hand, it is best not to stray too far from the meaning of the predefined indices. Otherwise, in the event that your text is combined with other text from other manuals, the index entries will not match up. Instead, define your own new index (@pxref{New Indices}). We recommend having a single index in the final document whenever possible, however many source indices you use, since then readers have only one place to look. Two or more source indices can be combined into one output index using the @code{@@synindex} or @code{@@syncodeindex} commands (@pxref{Combining Indices}). @node Indexing Commands @section Defining the Entries of an Index @cindex Defining indexing entries @cindex Index entries @cindex Entries for an index @cindex Specifying index entries @cindex Creating index entries The data to make an index come from many individual indexing commands scattered throughout the Texinfo source file. Each command says to add one entry to a particular index; after formatting, the index will give the current page number or node name as the reference.@refill An index entry consists of an indexing command at the beginning of a line followed, on the rest of the line, by the entry.@refill For example, this section begins with the following five entries for the concept index:@refill @example @@cindex Defining indexing entries @@cindex Index entries, defining @@cindex Entries for an index @@cindex Specifying index entries @@cindex Creating index entries @end example Each predefined index has its own indexing command---@code{@@cindex} for the concept index, @code{@@findex} for the function index, and so on, as listed in the previous section. @cindex Writing index entries @cindex Index entry writing Concept index entries consist of text. The best way to write an index is to choose entries that are terse yet clear. If you can do this, the index often looks better if the entries are not capitalized, but written just as they would appear in the middle of a sentence. (Capitalize proper names and acronyms that always call for upper case letters.) This is the case convention we use in most GNU manuals' indices. If you don't see how to make an entry terse yet clear, make it longer and clear---not terse and confusing. If many of the entries are several words long, the index may look better if you use a different convention: to capitalize the first word of each entry. But do not capitalize a case-sensitive name such as a C or Lisp function name or a shell command; that would be a spelling error. Whichever case convention you use, please use it consistently! Entries in indices other than the concept index are symbol names in programming languages, or program names; these names are usually case-sensitive, so use upper and lower case as required for them. @cindex Index font types By default, entries for a concept index are printed in a small roman font and entries for the other indices are printed in a small @code{@@code} font. You may change the way part of an entry is printed with the usual Texinfo commands, such as @code{@@file} for file names (@pxref{Marking Text}), and @code{@@r} for the normal roman font (@pxref{Fonts}). @quotation Caution Do not use a colon in an index entry. In Info, a colon separates the menu entry name from the node name, so a colon in the entry itself confuses Info. @xref{Menu Parts}, for more information about the structure of a menu entry. @end quotation @node Combining Indices @section Combining Indices @cindex Combining indices @cindex Indices, combining them Sometimes you will want to combine two disparate indices such as functions and concepts, perhaps because you have few enough entries that a separate index would look silly. You could put functions into the concept index by writing @code{@@cindex} commands for them instead of @code{@@findex} commands, and produce a consistent manual by printing the concept index with the title `Function and Concept Index' and not printing the `Function Index' at all; but this is not a robust procedure. It works only if your document is never included as part of another document that is designed to have a separate function index; if your document were to be included with such a document, the functions from your document and those from the other would not end up together. Also, to make your function names appear in the right font in the concept index, you would need to enclose every one of them between the braces of @code{@@code}. @menu * syncodeindex:: How to merge two indices, using @code{@@code} font for the merged-from index. * synindex:: How to merge two indices, using the default font of the merged-to index. @end menu @node syncodeindex @subsection @code{@@syncodeindex} @findex syncodeindex When you want to combine functions and concepts into one index, you should index the functions with @code{@@findex} and index the concepts with @code{@@cindex}, and use the @code{@@syncodeindex} command to redirect the function index entries into the concept index.@refill The @code{@@syncodeindex} command takes two arguments; they are the name of the index to redirect, and the name of the index to redirect it to. The template looks like this:@refill @example @@syncodeindex @var{from} @var{to} @end example @cindex Predefined names for indices @cindex Two letter names for indices @cindex Indices, two letter names @cindex Names for indices For this purpose, the indices are given two-letter names:@refill @table @samp @item cp concept index @item fn function index @item vr variable index @item ky key index @item pg program index @item tp data type index @end table Write an @code{@@syncodeindex} command before or shortly after the end-of-header line at the beginning of a Texinfo file. For example, to merge a function index with a concept index, write the following:@refill @example @@syncodeindex fn cp @end example @noindent This will cause all entries designated for the function index to merge in with the concept index instead.@refill To merge both a variables index and a function index into a concept index, write the following:@refill @example @group @@syncodeindex vr cp @@syncodeindex fn cp @end group @end example @cindex Fonts for indices The @code{@@syncodeindex} command puts all the entries from the `from' index (the redirected index) into the @code{@@code} font, overriding whatever default font is used by the index to which the entries are now directed. This way, if you direct function names from a function index into a concept index, all the function names are printed in the @code{@@code} font as you would expect.@refill @node synindex @subsection @code{@@synindex} @findex synindex The @code{@@synindex} command is nearly the same as the @code{@@syncodeindex} command, except that it does not put the `from' index entries into the @code{@@code} font; rather it puts them in the roman font. Thus, you use @code{@@synindex} when you merge a concept index into a function index.@refill @xref{Printing Indices & Menus}, for information about printing an index at the end of a book or creating an index menu in an Info file.@refill @node New Indices @section Defining New Indices @cindex Defining new indices @cindex Indices, defining new @cindex New index defining @findex defindex @findex defcodeindex In addition to the predefined indices, you may use the @code{@@defindex} and @code{@@defcodeindex} commands to define new indices. These commands create new indexing @@-commands with which you mark index entries. The @code{@@defindex} command is used like this: @example @@defindex @var{name} @end example The name of an index should be a two letter word, such as @samp{au}. For example: @example @@defindex au @end example This defines a new index, called the @samp{au} index. At the same time, it creates a new indexing command, @code{@@auindex}, that you can use to make index entries. Use this new indexing command just as you would use a predefined indexing command. For example, here is a section heading followed by a concept index entry and two @samp{au} index entries. @example @@section Cognitive Semantics @@cindex kinesthetic image schemas @@auindex Johnson, Mark @@auindex Lakoff, George @end example @noindent (Evidently, @samp{au} serves here as an abbreviation for ``author''.) In general, Texinfo constructs the new indexing command by concatenating the name of the index with @samp{index}; thus, defining an @samp{xy} index leads to the automatic creation of an @code{@@xyindex} command. Use the @code{@@printindex} command to print the index, as you do with the predefined indices. For example: @example @group @@node Author Index @@unnumbered Author Index @@printindex au @end group @end example The @code{@@defcodeindex} is like the @code{@@defindex} command, except that, in the printed output, it prints entries in an @code{@@code} font by default instead of a roman font. You should define new indices before the end-of-header line of a Texinfo file, and (of course) before any @code{@@synindex} or @code{@@syncodeindex} commands (@pxref{Texinfo File Header}). @node Insertions @chapter Special Insertions @cindex Inserting special characters and symbols @cindex Special insertions Texinfo provides several commands for inserting characters that have special meaning in Texinfo, such as braces, and for other graphic elements that do not correspond to simple characters you can type. @iftex These are: @itemize @bullet @item @samp{@@} and braces and commas. @item Whitespace within and around a sentence. @item Accents. @item Dots and bullets. @item The @TeX{} logo and the copyright symbol. @item The pounds currency symbol. @item The minus sign. @item Mathematical expressions. @item Glyphs for evaluation, macros, errors, etc. @item Footnotes. @item Images. @end itemize @end iftex @menu * Atsign Braces Comma:: Inserting @@ and @{@} and ,. * Inserting Space:: How to insert the right amount of space within a sentence. * Inserting Accents:: How to insert accents and special characters. * Dots Bullets:: How to insert dots and bullets. * TeX and copyright:: How to insert the @TeX{} logo and the copyright symbol. * euro:: How to insert the Euro currency symbol. * pounds:: How to insert the pounds currency symbol. * minus:: How to insert a minus sign. * math:: How to format a mathematical expression. * Glyphs:: How to indicate results of evaluation, expansion of macros, errors, etc. @end menu @node Atsign Braces Comma @section Inserting @@ and @{@} and @comma{} @cindex Special characters, inserting @cindex Commands to insert special characters @samp{@@} and curly braces are special characters in Texinfo. To insert these characters so they appear in text, you must put an @samp{@@} in front of these characters to prevent Texinfo from misinterpreting them. The comma `,' is a special character only in one uncommon context: it separates arguments to commands that take multiple arguments. @menu * Inserting an Atsign:: * Inserting Braces:: * Inserting a Comma:: @end menu @node Inserting an Atsign @subsection Inserting `@@' with @code{@@@@} @findex @@ @r{(literal @samp{@@})} @cindex Inserting @@ @r{(literal @samp{@@})} @code{@@@@} stands for a single @samp{@@} in either printed or Info output. Do not put braces after an @code{@@@@} command. @node Inserting Braces @subsection Inserting `@{' and `@}' with @code{@@@{} and @code{@@@}} @cindex Braces, inserting @findex @{ @r{(literal @samp{@{})} @findex @} @r{(literal @samp{@}})} @code{@@@{} stands for a single @samp{@{} in either printed or Info output. @code{@@@}} stands for a single @samp{@}} in either printed or Info output. Do not put braces after either an @code{@@@{} or an @code{@@@}} command.ppp @node Inserting a Comma @subsection Inserting `,' with @code{@@comma@{@}} @cindex Commas, inserting @findex comma Ordinarily, a comma `,' is a normal character that can be simply typed in your input where you need it. However, Texinfo uses the comma as a special character in one uncommon context: some commands, such as @code{@@acronym} (@pxref{acronym}) and @code{@@xref} (@pxref{Cross References}), as well as user-defined macros (@pxref{Defining Macros}), can take more than one argument. In these cases, the comma character is used to separate arguments. Since a comma chacter would confuse Texinfo's parsing for these commands, you must use the command @samp{@comma{}} instead if you want to have an actual comma in the output. Here are some examples: @example @@acronym@{ABC, A Bizarre @@comma@{@}@} @@xref@{Comma,, The @@comma@{@} symbol@} @@mymac@{One argument@@comma@{@} containing a comma@} @end example Although @comma{} can be used anywhere, there is no need for it anywhere except in this unusual case. @node Inserting Space @section Inserting Space @cindex Inserting space @cindex Spacing, inserting The following sections describe commands that control spacing of various kinds within and after sentences. @menu * Not Ending a Sentence:: Sometimes a . doesn't end a sentence. * Ending a Sentence:: Sometimes it does. * Multiple Spaces:: Inserting multiple spaces. * dmn:: How to format a dimension. @end menu @node Not Ending a Sentence @subsection Not Ending a Sentence @cindex Not ending a sentence @cindex Sentence non-ending punctuation @cindex Periods, inserting Depending on whether a period or exclamation point or question mark is inside or at the end of a sentence, less or more space is inserted after a period in a typeset manual. Since it is not always possible to determine when a period ends a sentence and when it is used in an abbreviation, special commands are needed in some circumstances. Usually, Texinfo can guess how to handle periods, so you do not need to use the special commands; you just enter a period as you would if you were using a typewriter, which means you put two spaces after the period, question mark, or exclamation mark that ends a sentence. @findex <colon> @r{(suppress end-of-sentence space)} Use the @code{@@:}@: command after a period, question mark, exclamation mark, or colon that should not be followed by extra space. For example, use @code{@@:}@: after periods that end abbreviations which are not at the ends of sentences. For example, @example The s.o.p.@@: has three parts @dots{} The s.o.p. has three parts @dots{} @end example @noindent @ifnottex produces @end ifnottex @iftex produces the following. If you look carefully at this printed output, you will see a little extraneous space after @samp{s.o.p.} in the second line. @end iftex @quotation The s.o.p.@: has three parts @dots{}@* The s.o.p. has three parts @dots{} @end quotation @noindent (Incidentally, @samp{s.o.p.} is an abbreviation for ``Standard Operating Procedure''.) @code{@@:} has no effect on the Info and HTML output. In Docbook and XML, the previous punctuation character (.?!:) is output as an entity instead of as the normal character: @samp{. ? ! :}. This gives further processors a chance to notice and not add the usual extra space. Do not put braces after @code{@@:} (or any non-alphabetic command). @node Ending a Sentence @subsection Ending a Sentence @cindex Ending a Sentence @cindex Sentence ending punctuation @findex . @r{(end of sentence)} @findex ! @r{(end of sentence)} @findex ? @r{(end of sentence)} Use @code{@@.}@: instead of a period, @code{@@!}@: instead of an exclamation point, and @code{@@?}@: instead of a question mark at the end of a sentence that ends with a capital letter. Otherwise, @TeX{} will think the letter is an abbreviation and will not insert the correct end-of-sentence spacing. Here is an example: @example Give it to M.I.B. and to M.E.W@@. Also, give it to R.J.C@@. Give it to M.I.B. and to M.E.W. Also, give it to R.J.C. @end example @noindent @ifnottex produces @end ifnottex @iftex produces the following. If you look carefully at this printed output, you will see a little more whitespace after the @samp{W} in the first line. @end iftex @quotation Give it to M.I.B. and to M.E.W@. Also, give it to R.J.C@.@* Give it to M.I.B. and to M.E.W. Also, give it to R.J.C. @end quotation In the Info file output, @code{@@.}@: is equivalent to a simple @samp{.}; likewise for @code{@@!}@: and @code{@@?}@:. The meanings of @code{@@:} and @code{@@.}@: in Texinfo are designed to work well with the Emacs sentence motion commands (@pxref{Sentences,,, emacs, The GNU Emacs Manual}). Do not put braces after any of these commands. @node Multiple Spaces @subsection Multiple Spaces @cindex Multiple spaces @cindex Whitespace, inserting @cindex Space, inserting horizontal @findex <space> @findex <tab> @findex <newline> Ordinarily, @TeX{} collapses multiple whitespace characters (space, tab, and newline) into a single space. Info output, on the other hand, preserves whitespace as you type it, except for changing a newline into a space; this is why it is important to put two spaces at the end of sentences in Texinfo documents. Occasionally, you may want to actually insert several consecutive spaces, either for purposes of example (what your program does with multiple spaces as input), or merely for purposes of appearance in headings or lists. Texinfo supports three commands: @code{@@@kbd{SPACE}}, @code{@@@kbd{TAB}}, and @code{@@@kbd{NL}}, all of which insert a single space into the output. (Here, @code{@@@kbd{SPACE}} represents an @samp{@@} character followed by a space, i.e., @samp{@@ }, and @kbd{TAB} and @kbd{NL} represent the tab character and end-of-line, i.e., when @samp{@@} is the last character on a line.) For example, @example Spacey@@ @@ @@ @@ example. @end example @noindent produces @example Spacey@ @ @ @ example. @end example Other possible uses of @code{@@@kbd{SPACE}} have been subsumed by @code{@@multitable} (@pxref{Multi-column Tables}). Do not follow any of these commands with braces. To produce a non-breakable space, see @ref{tie, @code{@@tie}}. @node dmn @subsection @code{@@dmn}@{@var{dimension}@}: Format a Dimension @cindex Thin space between number, dimension @cindex Dimension formatting @cindex Format a dimension @findex dmn At times, you may want to write @samp{12@dmn{pt}} or @samp{8.5@dmn{in}} with little or no space between the number and the abbreviation for the dimension. You can use the @code{@@dmn} command to do this. On seeing the command, @TeX{} inserts just enough space for proper typesetting; the Info formatting commands insert no space at all, since the Info file does not require it. To use the @code{@@dmn} command, write the number and then follow it immediately, with no intervening space, by @code{@@dmn}, and then by the dimension within braces. For example, @example A4 paper is 8.27@@dmn@{in@} wide. @end example @noindent produces @quotation A4 paper is 8.27@dmn{in} wide. @end quotation Not everyone uses this style. Some people prefer @w{@samp{8.27 in.@@:}} or @w{@samp{8.27 inches}} to @samp{8.27@@dmn@{in@}} in the Texinfo file. In these cases, however, the formatters may insert a line break between the number and the dimension, so use @code{@@w} (@pxref{w}). Also, if you write a period after an abbreviation within a sentence, you should write @samp{@@:} after the period to prevent @TeX{} from inserting extra whitespace, as shown here. @xref{Not Ending a Sentence}. @node Inserting Accents @section Inserting Accents @cindex Inserting accents @cindex Accents, inserting @cindex Floating accents, inserting Here is a table with the commands Texinfo provides for inserting floating accents. The commands with non-alphabetic names do not take braces around their argument (which is taken to be the next character). (Exception: @code{@@,} @emph{does} take braces around its argument.) This is so as to make the source as convenient to type and read as possible, since accented characters are very common in some languages. To get the true accented characters output in Info, and not just the ASCII transliterations, you can use the @option{--enable-encoding} option to @command{makeinfo} (@pxref{makeinfo options}). @findex " @r{(umlaut accent)} @cindex Umlaut accent @findex ' @r{(umlaut accent)} @cindex Acute accent @findex = @r{(macron accent)} @cindex Macron accent @findex ^ @r{(circumflex accent)} @cindex Circumflex accent @findex ` @r{(grave accent)} @cindex Grave accent @findex ~ @r{(tilde accent)} @cindex Tilde accent @findex , @r{(cedilla accent)} @cindex Cedilla accent @findex dotaccent @cindex Dot accent @findex H @r{(Hungarian umlaut accent)} @cindex Hungarian umlaut accent @findex ringaccent @cindex Ring accent @findex tieaccent @cindex Tie-after accent @findex u @r{(breve accent)} @cindex Breve accent @findex ubaraccent @cindex Underbar accent @findex udotaccent @cindex Underdot accent @findex v @r{(check accent)} @cindex Hacek accent @cindex Check accent @cindex Caron accent @multitable {@@questiondown@{@}} {Output} {hacek/check/caron accent} @item Command @tab Output @tab What @item @t{@@"o} @tab @"o @tab umlaut accent @item @t{@@'o} @tab @'o @tab acute accent @item @t{@@,@{c@}} @tab @,{c} @tab cedilla accent @item @t{@@=o} @tab @=o @tab macron/overbar accent @item @t{@@^o} @tab @^o @tab circumflex accent @item @t{@@`o} @tab @`o @tab grave accent @item @t{@@~o} @tab @~o @tab tilde accent @item @t{@@dotaccent@{o@}} @tab @dotaccent{o} @tab overdot accent @item @t{@@H@{o@}} @tab @H{o} @tab long Hungarian umlaut @item @t{@@ringaccent@{o@}} @tab @ringaccent{o} @tab ring accent @item @t{@@tieaccent@{oo@}} @tab @tieaccent{oo} @tab tie-after accent @item @t{@@u@{o@}} @tab @u{o} @tab breve accent @item @t{@@ubaraccent@{o@}} @tab @ubaraccent{o} @tab underbar accent @item @t{@@udotaccent@{o@}} @tab @udotaccent{o} @tab underdot accent @item @t{@@v@{o@}} @tab @v{o} @tab hacek/check/caron accent @end multitable This table lists the Texinfo commands for inserting other characters commonly used in languages other than English. @findex questiondown @cindex @questiondown{} @findex exclamdown @cindex @exclamdown{} @findex aa @cindex @aa{} @findex AA @cindex @AA{} @findex ae @cindex @ae{} @findex AE @cindex @AE{} @findex dotless @cindex @dotless{i} (dotless i) @cindex @dotless{j} (dotless j) @cindex Dotless i, j @findex l @cindex @l{} @findex L @cindex @L{} @findex o @cindex @o{} @findex O @cindex @O{} @findex oe @cindex @oe{} @findex OE @cindex @OE{} @cindex Romance ordinals @cindex Ordinals, Romance @cindex Feminine ordinal @findex ordf @cindex @ordf{} @cindex Masculine ordinal @findex ordm @cindex @ordm{} @findex ss @cindex @ss{} @cindex Es-zet @cindex Sharp S @cindex German S @multitable {x@@questiondown@{@}} {oe OE} {es-zet or sharp S} @item @t{@@exclamdown@{@}} @tab @exclamdown{} @tab upside-down ! @item @t{@@questiondown@{@}} @tab @questiondown{} @tab upside-down ? @item @t{@@aa@{@} @@AA@{@}} @tab @aa{} @AA{} @tab a,A with circle @item @t{@@ae@{@} @@AE@{@}} @tab @ae{} @AE{} @tab ae,AE ligatures @item @t{@@dotless@{i@}} @tab @dotless{i} @tab dotless i @item @t{@@dotless@{j@}} @tab @dotless{j} @tab dotless j @item @t{@@l@{@} @@L@{@}} @tab @l{} @L{} @tab suppressed-L,l @item @t{@@o@{@} @@O@{@}} @tab @o{} @O{} @tab O,o with slash @item @t{@@oe@{@} @@OE@{@}} @tab @oe{} @OE{} @tab oe,OE ligatures @item @t{@@ordf@{@} @@ordm@{@}} @tab @ordf{} @ordm{} @tab Spanish ordinals @item @t{@@ss@{@}} @tab @ss{} @tab es-zet or sharp S @end multitable @node Dots Bullets @section Inserting Ellipsis and Bullets @cindex Dots, inserting @cindex Bullets, inserting @cindex Ellipsis, inserting @cindex Inserting ellipsis @cindex Inserting dots @cindex Special typesetting commands @cindex Typesetting commands for dots, etc. An @dfn{ellipsis} (a line of dots) is not typeset as a string of periods, so a special command is used for ellipsis in Texinfo. The @code{@@bullet} command is special, too. Each of these commands is followed by a pair of braces, @samp{@{@}}, without any whitespace between the name of the command and the braces. (You need to use braces with these commands because you can use them next to other text; without the braces, the formatters would be confused. @xref{Command Syntax, , @@-Command Syntax}, for further information.)@refill @menu * dots:: How to insert dots @dots{} * bullet:: How to insert a bullet. @end menu @node dots @subsection @code{@@dots}@{@} (@dots{}) and @code{@@enddots}@{@} (@enddots{}) @findex dots @findex enddots @cindex Inserting dots @cindex Dots, inserting Use the @code{@@dots@{@}} command to generate an ellipsis, which is three dots in a row, appropriately spaced @dots{} like so. Do not simply write three periods in the input file; that would work for the Info file output, but would produce the wrong amount of space between the periods in the printed manual. Similarly, the @code{@@enddots@{@}} command generates an end-of-sentence ellipsis, which has different spacing afterwards, @enddots{} Look closely to see the difference. @iftex Here is an ellipsis: @dots{} Here are three periods in a row: ... In printed output, the three periods in a row are closer together than the dots in the ellipsis. @end iftex @node bullet @subsection @code{@@bullet}@{@} (@bullet{}) @findex bullet Use the @code{@@bullet@{@}} command to generate a large round dot, or the closest possible thing to one. In Info, an asterisk is used.@refill Here is a bullet: @bullet{} When you use @code{@@bullet} in @code{@@itemize}, you do not need to type the braces, because @code{@@itemize} supplies them. (@xref{itemize, , @code{@@itemize}}.)@refill @node TeX and copyright @section Inserting @TeX{} and Legal Symbols: @copyright{}, @registeredsymbol{} The logo `@TeX{}' is typeset in a special fashion and it needs an @@-command. The copyright and registered symbols, `@copyright{}' and `@registeredsymbol{}', is also special. Each of these commands is followed by a pair of braces, @samp{@{@}}, without any whitespace between the name of the command and the braces. @menu * tex:: The @TeX{} logos. * copyright symbol:: The copyright symbol (c in a circle). * registered symbol:: The registered symbol (R in a circle). @end menu @node tex @subsection @code{@@TeX}@{@} (@TeX{}) and @code{@@LaTeX}@{@} (@LaTeX{}) @findex TeX @findex LaTeX Use the @code{@@TeX@{@}} command to generate `@TeX{}'. In a printed manual, this is a special logo that is different from three ordinary letters. In Info, it just looks like @samp{TeX}. Similarly, use the @code{@@LaTeX@{@}} command to generate `@LaTeX{}', which is even more special in printed manuals (and different from the incorrect @code{La@@TeX@{@}}. In Info, the result is just @samp{LaTeX}. (@LaTeX{} is another macro package built on top of @TeX{}, very loosely analogous to Texinfo in that it emphasizes logical structure, but much (much) larger.) The spelling of these commands are unusual among Texinfo commands in that they use both uppercase and lowercase letters. @node copyright symbol @subsection @code{@@copyright@{@}} (@copyright{}) @findex copyright Use the @code{@@copyright@{@}} command to generate the copyright symbol, `@copyright{}'. Where possible, this is a @samp{c} inside a circle; in Info, this is @samp{(C)}. @node registered symbol @subsection @code{@@registeredsymbol@{@}} (@registeredsymbol{}) @findex registeredsymbol Use the @code{@@registeredsymbol@{@}} command to generate the registered symbol, `@registeredsymbol{}'. Where possible, this is an @samp{R} inside a circle; in Info, this is @samp{(R)}. @node euro @section @code{@@euro}@{@} (@euro{}): Euro currency symbol @findex euro Use the @code{@@euro@{@}} command to generate `@euro{}'. Where possible, this is the symbol for the Euro currency, invented as part of the European economic unification relatively recently. In plain Info, it is the word @samp{Euro }. (The space is included in the text transliteration since typically there would be no space after the symbol, so it would be inappropriate to have a space in the source document.) Texinfo cannot magically synthesize support for the Euro symbol where the underlying system (fonts, software, whatever) does not support it. Therefore, in many cases it is preferable to use the word ``Euro''. (In banking circles, the abbreviation for the Euro is EUR.) @cindex ISO 8859-15 @cindex Latin 9 In order to get the Euro symbol in encoded Info output, for example, it is necessary to specify @code{@@documentencoding ISO-8859-15}. (@xref{documentencoding,,@code{@@documentencoding}}.) The Euro symbol is in ISO 8859-15 (aka Latin@tie{}9), and is @emph{not} in the more widely-used and supported ISO 8859-1 (Latin@tie{}1). @node pounds @section @code{@@pounds}@{@} (@pounds{}): Pounds Sterling @findex pounds Use the @code{@@pounds@{@}} command to generate `@pounds{}'. Where possible, this is the symbol for the currency pounds sterling. In Info, it is a @samp{#}. @node minus @section @code{@@minus}@{@} (@minus{}): Inserting a Minus Sign @findex minus @cindex Em dash, compared to minus sign @cindex Hyphen, compared to minus Use the @code{@@minus@{@}} command to generate a minus sign. In a fixed-width font, this is a single hyphen, but in a proportional font, the symbol is the customary length for a minus sign---a little longer than a hyphen, shorter than an em-dash: @display @samp{@minus{}} is a minus sign generated with @samp{@@minus@{@}}, `-' is a hyphen generated with the character @samp{-}, `---' is an em-dash for text. @end display @noindent In the fixed-width font used by Info, @code{@@minus@{@}} is the same as a hyphen. You should not use @code{@@minus@{@}} inside @code{@@code} or @code{@@example} because the width distinction is not made in the fixed-width font they use. When you use @code{@@minus} to specify the mark beginning each entry in an itemized list, you do not need to type the braces (@pxref{itemize, , @code{@@itemize}}). @node math @section @code{@@math}: Inserting Mathematical Expressions @findex math @cindex Mathematical expressions @cindex Formulas, mathematical You can write a short mathematical expression with the @code{@@math} command. Write the mathematical expression between braces, like this: @example @@math@{(a + b)(a + b) = a^2 + 2ab + b^2@} @end example @iftex @noindent This produces the following in @TeX{}: @display @math{(a + b)(a + b) = a^2 + 2ab + b^2} @end display @noindent and the following in other formats: @end iftex @ifnottex @noindent This produces the following in Info and HTML: @end ifnottex @example (a + b)(a + b) = a^2 + 2ab + b^2 @end example Thus, the @code{@@math} command has no effect on the Info and HTML output; @command{makeinfo} just reproduces the input, it does not try to interpret the mathematics in any way. @code{@@math} implies @code{@@tex}. This not only makes it possible to write superscripts and subscripts (as in the above example), but also allows you to use any of the plain @TeX{} math control sequences. It's conventional to use @samp{\} instead of @samp{@@} for these commands. As in: @example @@math@{\sin 2\pi \equiv \cos 3\pi@} @end example @iftex @noindent which looks like this in @TeX{}: @display @math{\sin 2\pi \equiv \cos 3\pi} @end display @noindent and @end iftex @noindent which looks like the input in Info and HTML: @example \sin 2\pi \equiv \cos 3\pi @end example @findex \ @r{(literal \ in @code{@@math})} Since @samp{\} is an escape character inside @code{@@math}, you can use @code{@@\} to get a literal backslash (@code{\\} will work in @TeX{}, but you'll get the literal @samp{\\} in Info). @code{@@\} is not defined outside of @code{@@math}, since a @samp{\} ordinarily produces a literal @samp{\}. @cindex Displayed equations @cindex Equations, displayed For displayed equations, you must at present use @TeX{} directly (@pxref{Raw Formatter Commands}). @node Glyphs @section Glyphs for Examples @cindex Glyphs @cindex Examples, glyphs for In Texinfo, code is often illustrated in examples that are delimited by @code{@@example} and @code{@@end example}, or by @code{@@lisp} and @code{@@end lisp}. In such examples, you can indicate the results of evaluation or an expansion using @samp{@result{}} or @samp{@expansion{}}. Likewise, there are commands to insert glyphs to indicate printed output, error messages, equivalence of expressions, and the location of point.@refill The glyph-insertion commands do not need to be used within an example, but most often they are. Every glyph-insertion command is followed by a pair of left- and right-hand braces.@refill @menu * Glyphs Summary:: * result:: How to show the result of expression. * expansion:: How to indicate an expansion. * Print Glyph:: How to indicate printed output. * Error Glyph:: How to indicate an error message. * Equivalence:: How to indicate equivalence. * Point Glyph:: How to indicate the location of point. @end menu @node Glyphs Summary @subsection Glyphs Summary Here are the different glyph commands:@refill @table @asis @item @result{} @code{@@result@{@}} points to the result of an expression.@refill @item @expansion{} @code{@@expansion@{@}} shows the results of a macro expansion.@refill @item @print{} @code{@@print@{@}} indicates printed output.@refill @item @error{} @code{@@error@{@}} indicates that the following text is an error message.@refill @item @equiv{} @code{@@equiv@{@}} indicates the exact equivalence of two forms.@refill @item @point{} @code{@@point@{@}} shows the location of point.@refill @end table @menu * result:: * expansion:: * Print Glyph:: * Error Glyph:: * Equivalence:: * Point Glyph:: @end menu @node result @subsection @code{@@result@{@}} (@result{}): Indicating Evaluation @cindex Result of an expression @cindex Indicating evaluation @cindex Evaluation glyph @cindex Value of an expression, indicating @findex result Use the @code{@@result@{@}} command to indicate the result of evaluating an expression.@refill @iftex The @code{@@result@{@}} command is displayed as @samp{@result{}} in the printed output and as @samp{=>} in other formats. @end iftex @ifnottex The @code{@@result@{@}} command is displayed as @samp{@result{}} in Info and HTML and as a true double stemmed arrow in the printed output. @end ifnottex Thus, the following, @lisp (cdr '(1 2 3)) @result{} (2 3) @end lisp @noindent may be read as ``@code{(cdr '(1 2 3))} evaluates to @code{(2 3)}''. @node expansion @subsection @code{@@expansion@{@}} (@expansion{}): Indicating an Expansion @cindex Expansion, indicating @cindex Macro expansion, indicating @findex expansion When an expression is a macro call, it expands into a new expression. You can indicate the result of the expansion with the @code{@@expansion@{@}} command.@refill @iftex The @code{@@expansion@{@}} command is displayed as @samp{@expansion{}} in the printed output. and as @samp{==>} in other formats. @end iftex @ifnottex The @code{@@expansion@{@}} command is displayed as @samp{@expansion{}} in Info and HTML, and as a long arrow with a flat base in the printed output. @end ifnottex @need 700 For example, the following @example @group @@lisp (third '(a b c)) @@expansion@{@} (car (cdr (cdr '(a b c)))) @@result@{@} c @@end lisp @end group @end example @noindent produces @lisp @group (third '(a b c)) @expansion{} (car (cdr (cdr '(a b c)))) @result{} c @end group @end lisp @noindent which may be read as: @quotation @code{(third '(a b c))} expands to @code{(car (cdr (cdr '(a b c))))}; the result of evaluating the expression is @code{c}. @end quotation @noindent Often, as in this case, an example looks better if the @code{@@expansion@{@}} and @code{@@result@{@}} commands are indented. @node Print Glyph @subsection @code{@@print@{@}} (@print{}): Indicating Printed Output @cindex Printed output, indicating @findex print Sometimes an expression will print output during its execution. You can indicate the printed output with the @code{@@print@{@}} command.@refill @iftex The @code{@@print@{@}} command is displayed as @samp{-|} in Info and HTML and as @samp{@print{}} in the printed output. @end iftex @ifnottex The @code{@@print@{@}} command is displayed as @samp{@print{}} in Info and HTML and (similarly) as a horizontal dash butting against a vertical bar in the printed output. @end ifnottex In the following example, the printed text is indicated with @samp{@print{}}, and the value of the expression follows on the last line. @lisp @group (progn (print 'foo) (print 'bar)) @print{} foo @print{} bar @result{} bar @end group @end lisp @noindent In a Texinfo source file, this example is written as follows: @lisp @group @@lisp (progn (print 'foo) (print 'bar)) @@print@{@} foo @@print@{@} bar @@result@{@} bar @@end lisp @end group @end lisp @node Error Glyph @subsection @code{@@error@{@}} (@error{}): Indicating an Error Message @cindex Error message, indicating @findex error A piece of code may cause an error when you evaluate it. You can designate the error message with the @code{@@error@{@}} command.@refill @iftex The @code{@@error@{@}} command is displayed as @samp{error-->} in Info and HTML and as @samp{@error{}} in the printed output. @end iftex @ifnottex The @code{@@error@{@}} command is displayed as @samp{@error{}} in Info and HTML and as the word `error' in a box in the printed output. @end ifnottex @need 700 Thus, @example @@lisp (+ 23 'x) @@error@{@} Wrong type argument: integer-or-marker-p, x @@end lisp @end example @noindent produces @lisp (+ 23 'x) @error{} Wrong type argument: integer-or-marker-p, x @end lisp @noindent This indicates that the following error message is printed when you evaluate the expression: @lisp Wrong type argument: integer-or-marker-p, x @end lisp @samp{@error{}} itself is not part of the error message. @node Equivalence @subsection @code{@@equiv@{@}} (@equiv{}): Indicating Equivalence @cindex Equivalence, indicating @findex equiv Sometimes two expressions produce identical results. You can indicate the exact equivalence of two forms with the @code{@@equiv@{@}} command.@refill @iftex The @code{@@equiv@{@}} command is displayed as @samp{==} in Info and HTML and as @samp{@equiv{}} in the printed output. @end iftex @ifnottex The @code{@@equiv@{@}} command is displayed as @samp{@equiv{}} in Info and HTML and as a standard mathematical equivalence sign (three parallel horizontal lines) in the printed output. @end ifnottex Thus, @example @@lisp (make-sparse-keymap) @@equiv@{@} (list 'keymap) @@end lisp @end example @noindent produces @lisp (make-sparse-keymap) @equiv{} (list 'keymap) @end lisp @noindent This indicates that evaluating @code{(make-sparse-keymap)} produces identical results to evaluating @code{(list 'keymap)}. @node Point Glyph @subsection @code{@@point@{@}} (@point{}): Indicating Point in a Buffer @cindex Point, indicating in a buffer @findex point Sometimes you need to show an example of text in an Emacs buffer. In such examples, the convention is to include the entire contents of the buffer in question between two lines of dashes containing the buffer name.@refill You can use the @samp{@@point@{@}} command to show the location of point in the text in the buffer. (The symbol for point, of course, is not part of the text in the buffer; it indicates the place @emph{between} two characters where point is located.)@refill @iftex The @code{@@point@{@}} command is displayed as @samp{-!-} in Info and HTML and as @samp{@point{}} in the printed output. @end iftex @ifnottex The @code{@@point@{@}} command is displayed as @samp{@point{}} in Info and HTML and as a small five pointed star in the printed output. @end ifnottex The following example shows the contents of buffer @file{foo} before and after evaluating a Lisp command to insert the word @code{changed}.@refill @example @group ---------- Buffer: foo ---------- This is the @point{}contents of foo. ---------- Buffer: foo ---------- @end group @end example @example @group (insert "changed ") @result{} nil ---------- Buffer: foo ---------- This is the changed @point{}contents of foo. ---------- Buffer: foo ---------- @end group @end example In a Texinfo source file, the example is written like this:@refill @example @@example ---------- Buffer: foo ---------- This is the @@point@{@}contents of foo. ---------- Buffer: foo ---------- (insert "changed ") @@result@{@} nil ---------- Buffer: foo ---------- This is the changed @@point@{@}contents of foo. ---------- Buffer: foo ---------- @@end example @end example @node Breaks @chapter Forcing and Preventing Breaks @cindex Forcing line and page breaks @cindex Making line and page breaks @cindex Preventing line and page breaks @cindex Line breaks Usually, a Texinfo file is processed both by @TeX{} and by one of the Info formatting commands. Line, paragraph, or page breaks sometimes occur in the `wrong' place in one or other form of output. You must ensure that text looks right both in the printed manual and in the Info file. @cindex White space, excessive @cindex Page breaks For example, in a printed manual, page breaks may occur awkwardly in the middle of an example; to prevent this, you can hold text together using a grouping command that keeps the text from being split across two pages. Conversely, you may want to force a page break where none would occur normally. Fortunately, problems like these do not often arise. When they do, use the break, break prevention, or pagination commands. @menu * Break Commands:: Summary of break-related commands. * Line Breaks:: Forcing line breaks. * - and hyphenation:: Helping @TeX{} with hyphenation points. * w:: Preventing unwanted line breaks in text. * tie:: Inserting an unbreakable but varying space. * sp:: Inserting blank lines. * page:: Forcing the start of a new page. * group:: Preventing unwanted page breaks. * need:: Another way to prevent unwanted page breaks. @end menu @node Break Commands @section Break Commands The break commands create or allow line and paragraph breaks: @table @code @item @@* Force a line break. @item @@sp @var{n} Skip @var{n} blank lines. @item @@- Insert a discretionary hyphen. @item @@hyphenation@{@var{hy-phen-a-ted words}@} Define hyphen points in @var{hy-phen-a-ted words}. @end table These commands hold text together on a single line: @table @code @item @@w@{@var{text}@} Prevent @var{text} from being split and hyphenated across two lines. @item @@tie@{@} Insert a normal interword space at which a line break may not occur. @end table @iftex @sp 1 @end iftex The pagination commands apply only to printed output, since Info files do not have pages. @table @code @item @@page Start a new page in the printed manual. @item @@group Hold text together that must appear on one printed page. @item @@need @var{mils} Start a new printed page if not enough space on this one. @end table @node Line Breaks @section @code{@@*} and @code{@@/}: Generate and Allow Line Breaks @findex * @r{(force line break)} @findex / @r{(allow line break)} @cindex Line breaks @cindex Breaks in a line @cindex Force line break @cindex Allow line break The @code{@@*} command forces a line break in both the printed manual and in Info. The @code{@@/} command allows a line break (printed manual only). Here is an example with @code{@@*}: @example This line @@* is broken @@*in two places. @end example @noindent produces @example @group This line is broken in two places. @end group @end example The @code{@@/} command can be useful within a url (@pxref{uref,,@code{@@uref}}), which tend to be long and are otherwise unbreakable. For example: @example The official Texinfo home page is on the GNU web site: @@uref@{http://www.gnu.org/@@/software/@@/gnu/@@/texinfo@}. @end example @noindent produces @display The official Texinfo home page is on the GNU web site: @uref{http://www.gnu.org/@/software/@/gnu/@/texinfo}. @end display @noindent Without the @code{@@/} commands, @TeX{} would have nowhere to break the line. @code{@@/} has no effect in the online output. @node - and hyphenation @section @code{@@-} and @code{@@hyphenation}: Helping @TeX{} Hyphenate @findex - @r{(discretionary hyphen)} @findex hyphenation @cindex Hyphenation, helping @TeX{} do @cindex Fine-tuning, and hyphenation Although @TeX{}'s hyphenation algorithm is generally pretty good, it does miss useful hyphenation points from time to time. (Or, far more rarely, insert an incorrect hyphenation.) So, for documents with an unusual vocabulary or when fine-tuning for a printed edition, you may wish to help @TeX{} out. Texinfo supports two commands for this: @table @code @item @@- Insert a discretionary hyphen, i.e., a place where @TeX{} can (but does not have to) hyphenate. This is especially useful when you notice an overfull hbox is due to @TeX{} missing a hyphenation (@pxref{Overfull hboxes}). @TeX{} will not insert any hyphenation points itself into a word containing @code{@@-}. @item @@hyphenation@{@var{hy-phen-a-ted words}@} Tell @TeX{} how to hyphenate @var{hy-phen-a-ted words}. As shown, you put a @samp{-} at each hyphenation point. For example: @example @@hyphenation@{man-u-script man-u-scripts@} @end example @noindent @TeX{} only uses the specified hyphenation points when the words match exactly, so give all necessary variants. @end table Info output is not hyphenated, so these commands have no effect there. @node w @section @code{@@w}@{@var{text}@}: Prevent Line Breaks @findex w @r{(prevent line break)} @cindex Line breaks, preventing @code{@@w@{@var{text}@}} outputs @var{text} and prohibits line breaks within @var{text}, for both @TeX{} and @command{makeinfo}. @cindex Non-breakable space, fixed @cindex Unbreakable space, fixed Thus, you can use @code{@@w} to produce a non-breakable space, fixed at the width of a normal interword space: @example @@w@{ @} @@w@{ @} @@w@{ @} indentation. @end example @noindent produces: @display @w{ } @w{ } @w{ } indentation. @end display The space from @code{@@w@{@w{ }@}}, as well as being non-breakable, also will not stretch or shrink. Sometimes that is what you want, for instance if you're doing indenting manual. However, usually you want a normal interword space that does stretch and shrink (in the printed output); see the @code{@@tie} command in the next section. @cindex Hyphenation, preventing You can also use the @code{@@w} command to prevent @TeX{} from automatically hyphenating a long name or phrase that happens to fall near the end of a line. @command{makeinfo} does not ever hyphenate words. @cindex Keyword expansion, preventing @cindex Version control keywords, preventing expansion of @cindex $Id expansion, preventing You can also use @code{@@w} to avoid unwanted keyword expansion in source control systems. For example, to literally write @t{@w{$}Id$} in your document, use @code{@@w@{$@}Id$}. @node tie @section @code{@@tie@{@}}: Inserting an Unbreakable Space @findex tie @r{(unbreakable interword space)} @cindex Tied space @cindex Non-breakable space, variable @cindex Unbreakable space, variable The @code{@@tie@{@}} command produces a normal interword space at which a line break may not occur. Always write it with following (empty) braces, as usual for commands used within a paragraph. Here's an example: @example @@TeX@{@} was written by Donald E.@@tie@{@}Knuth. @end example @noindent produces: @display @TeX{} was written by Donald E.@tie{}Knuth. @end display There are two important differences between @code{@@tie@{@}} and @code{@@w@{@w{ }@}}: @itemize @item The space produced by @code{@@tie@{@}} will stretch and shrink slightly along with the normal interword spaces in the paragraph; the space produced by @code{@@w@{@w{ }@}} will not vary. @item @code{@@tie@{@}} allows hyphenation of the surrounding words, while @code{@@w@{@w{ }@}} inhibits hyphenation of those words (for @TeX{}nical reasons, namely that it produces an @samp{\hbox}). @end itemize @node sp @section @code{@@sp} @var{n}: Insert Blank Lines @findex sp @r{(line spacing)} @cindex Space, inserting vertical @cindex Blank lines @cindex Line spacing A line beginning with and containing only @code{@@sp @var{n}} generates @var{n} blank lines of space in both the printed manual and the Info file. @code{@@sp} also forces a paragraph break. For example, @example @@sp 2 @end example @noindent generates two blank lines. The @code{@@sp} command is most often used in the title page.@refill @ignore @c node br, page, sp, Breaks @comment node-name, next, previous, up @c section @code{@@br}: Generate Paragraph Breaks @findex br @r{(paragraph breaks)} @cindex Paragraph breaks @cindex Breaks in a paragraph The @code{@@br} command forces a paragraph break. It inserts a blank line. You can use the command within or at the end of a line. If used within a line, the @code{@@br@{@}} command must be followed by left and right braces (as shown here) to mark the end of the command.@refill @need 700 For example, @example @group This line @@br@{@}contains and is ended by paragraph breaks@@br and is followed by another line. @end group @end example @noindent produces @example @group This line contains and is ended by paragraph breaks and is followed by another line. @end group @end example The @code{@@br} command is seldom used. @end ignore @node page @section @code{@@page}: Start a New Page @cindex Page breaks @findex page A line containing only @code{@@page} starts a new page in a printed manual. The command has no effect on Info files since they are not paginated. An @code{@@page} command is often used in the @code{@@titlepage} section of a Texinfo file to start the copyright page. @node group @comment node-name, next, previous, up @section @code{@@group}: Prevent Page Breaks @cindex Group (hold text together vertically) @cindex Holding text together vertically @cindex Vertically holding text together @findex group The @code{@@group} command (on a line by itself) is used inside an @code{@@example} or similar construct to begin an unsplittable vertical group, which will appear entirely on one page in the printed output. The group is terminated by a line containing only @code{@@end group}. These two lines produce no output of their own, and in the Info file output they have no effect at all.@refill @c Once said that these environments @c turn off vertical spacing between ``paragraphs''. @c Also, quotation used to work, but doesn't in texinfo-2.72 Although @code{@@group} would make sense conceptually in a wide variety of contexts, its current implementation works reliably only within @code{@@example} and variants, and within @code{@@display}, @code{@@format}, @code{@@flushleft} and @code{@@flushright}. @xref{Quotations and Examples}. (What all these commands have in common is that each line of input produces a line of output.) In other contexts, @code{@@group} can cause anomalous vertical spacing.@refill @need 750 This formatting requirement means that you should write: @example @group @@example @@group @dots{} @@end group @@end example @end group @end example @noindent with the @code{@@group} and @code{@@end group} commands inside the @code{@@example} and @code{@@end example} commands. The @code{@@group} command is most often used to hold an example together on one page. In this Texinfo manual, more than 100 examples contain text that is enclosed between @code{@@group} and @code{@@end group}. If you forget to end a group, you may get strange and unfathomable error messages when you run @TeX{}. This is because @TeX{} keeps trying to put the rest of the Texinfo file onto the one page and does not start to generate error messages until it has processed considerable text. It is a good rule of thumb to look for a missing @code{@@end group} if you get incomprehensible error messages in @TeX{}.@refill @node need @comment node-name, next, previous, up @section @code{@@need @var{mils}}: Prevent Page Breaks @cindex Need space at page bottom @findex need A line containing only @code{@@need @var{n}} starts a new page in a printed manual if fewer than @var{n} mils (thousandths of an inch) remain on the current page. Do not use braces around the argument @var{n}. The @code{@@need} command has no effect on Info files since they are not paginated.@refill @need 800 This paragraph is preceded by an @code{@@need} command that tells @TeX{} to start a new page if fewer than 800 mils (eight-tenths inch) remain on the page. It looks like this:@refill @example @group @@need 800 This paragraph is preceded by @dots{} @end group @end example The @code{@@need} command is useful for preventing orphans (single lines at the bottoms of printed pages).@refill @node Definition Commands @chapter Definition Commands @cindex Definition commands The @code{@@deffn} command and the other @dfn{definition commands} enable you to describe functions, variables, macros, commands, user options, special forms and other such artifacts in a uniform format.@refill In the Info file, a definition causes the entity category---`Function', `Variable', or whatever---to appear at the beginning of the first line of the definition, followed by the entity's name and arguments. In the printed manual, the command causes @TeX{} to print the entity's name and its arguments on the left margin and print the category next to the right margin. In both output formats, the body of the definition is indented. Also, the name of the entity is entered into the appropriate index: @code{@@deffn} enters the name into the index of functions, @code{@@defvr} enters it into the index of variables, and so on (@pxref{Predefined Indices}). A manual need not and should not contain more than one definition for a given name. An appendix containing a summary should use @code{@@table} rather than the definition commands.@refill @menu * Def Cmd Template:: Writing descriptions using definition commands. * Def Cmd Continuation Lines:: Continuing the heading over source lines. * Optional Arguments:: Handling optional and repeated arguments. * deffnx:: Group two or more `first' lines. * Def Cmds in Detail:: Reference for all the definition commands. * Def Cmd Conventions:: Conventions for writing definitions. * Sample Function Definition:: An example. @end menu @node Def Cmd Template @section The Template for a Definition @cindex Definition template @cindex Template for a definition The @code{@@deffn} command is used for definitions of entities that resemble functions. To write a definition using the @code{@@deffn} command, write the @code{@@deffn} command at the beginning of a line and follow it on the same line by the category of the entity, the name of the entity itself, and its arguments (if any). Then write the body of the definition on succeeding lines. (You may embed examples in the body.) Finally, end the definition with an @code{@@end deffn} command written on a line of its own. The other definition commands follow the same format: a line with the @code{@@def@dots{}} command and whatever arguments are appropriate for that command; the body of the definition; and a corresponding @code{@@end} line. The template for a definition looks like this: @example @group @@deffn @var{category} @var{name} @var{arguments}@dots{} @var{body-of-definition} @@end deffn @end group @end example @need 700 @noindent For example, @example @group @@deffn Command forward-word count This command moves point forward @@var@{count@} words (or backward if @@var@{count@} is negative). @dots{} @@end deffn @end group @end example @noindent produces @quotation @deffn Command forward-word count This function moves point forward @var{count} words (or backward if @var{count} is negative). @dots{} @end deffn @end quotation Capitalize the category name like a title. If the name of the category contains spaces, as in the phrase `Interactive Command', enclose it in braces. For example: @example @group @@deffn @{Interactive Command@} isearch-forward @dots{} @@end deffn @end group @end example @noindent Otherwise, the second word will be mistaken for the name of the entity. As a general rule, when any of the arguments in the heading line @emph{except} the last one are more than one word, you need to enclose them in braces. Some of the definition commands are more general than others. The @code{@@deffn} command, for example, is the general definition command for functions and the like---for entities that may take arguments. When you use this command, you specify the category to which the entity belongs. Three predefined, specialized variations (@code{@@defun}, @code{@@defmac}, and @code{@@defspec}) specify the category for you: ``Function'', ``Macro'', and ``Special Form'' respectively. (In Lisp, a special form is an entity much like a function.) Similarly, the general @code{@@defvr} command is accompanied by several specialized variations for describing particular kinds of variables. @xref{Sample Function Definition}, for a detailed example of a function definition, including the use of @code{@@example} inside the definition. @cindex Macros in definition commands Unfortunately, due to implementation difficulties, macros are not expanded in @code{@@deffn} and all the other definition commands. @node Def Cmd Continuation Lines @section Definition Command Continuation Lines @cindex Continuation lines in definition commands @cindex Definition command headings, continuing @cindex @samp{@@} as continuation in definition commands The heading line of a definition command can get very long. Therefore, Texinfo has a special syntax allowing them to be continued over multiple lines of the source file: a lone @samp{@@} at the end of each line to be continued. Here's an example: @example @@defun fn-name @@ arg1 arg2 arg3 This is the basic continued defun. @@end defun @end example @noindent produces: @defun fn-name @ arg1 arg2 arg3 This is the basic continued defun. @end defun @noindent As you can see, the continued lines are combined, as if they had been typed on one source line. Although this example only shows a one-line continuation, continuations may extend over any number of lines; simply put an @code{@@} at the end of each line to be continued. The @code{@@} character does not have to be the last character on the physical line: whitespace is allowed (and ignored) afterwards. @cindex Whitespace, collapsed around continuations @cindex Collapsing whitespace around continuations In general, any number of spaces or tabs around the @code{@@} continuation character, both on the line with the @code{@@} and on the continued line, are collapsed into a single space. There is one exception: the Texinfo processors will not fully collapse whitespace around a continuation inside braces. For example: @example @@deffn @{Category @@ Name@} @dots{} @end example @noindent The output (not shown) has excess space between `Category' and `Name'. In this case, simply elide any unwanted whitespace in your input, or put the continuation @code{@@} outside braces. @code{@@} does not (currently) function as a continuation character in @emph{any} other context. Ordinarily, @samp{@@} followed by a whitespace character (space, tab, newline) produces a normal interword space (@pxref{Multiple Spaces}). @node Optional Arguments @section Optional and Repeated Arguments @cindex Optional and repeated arguments @cindex Repeated and optional arguments @cindex Arguments, repeated and optional @cindex Syntax, optional & repeated arguments @cindex Meta-syntactic chars for arguments Some entities take optional or repeated arguments, which may be specified by a distinctive glyph that uses square brackets and ellipses. For @w{example}, a special form often breaks its argument list into separate arguments in more complicated ways than a straightforward function. @c This is consistent with Emacs Lisp Reference manual An argument enclosed within square brackets is optional. Thus, [@var{optional-arg}] means that @var{optional-arg} is optional. An argument followed by an ellipsis is optional and may be repeated more than once. @c This is consistent with Emacs Lisp Reference manual Thus, @var{repeated-args}@samp{@dots{}} stands for zero or more arguments. Parentheses are used when several arguments are grouped into additional levels of list structure in Lisp. Here is the @code{@@defspec} line of an example of an imaginary special form: @quotation @defspec foobar (@var{var} [@var{from} @var{to} [@var{inc}]]) @var{body}@dots{} @end defspec @tex \vskip \parskip @end tex @end quotation @noindent In this example, the arguments @var{from} and @var{to} are optional, but must both be present or both absent. If they are present, @var{inc} may optionally be specified as well. These arguments are grouped with the argument @var{var} into a list, to distinguish them from @var{body}, which includes all remaining elements of the form.@refill In a Texinfo source file, this @code{@@defspec} line is written like this (except it would not be split over two lines, as it is in this example).@refill @example @group @@defspec foobar (@@var@{var@} [@@var@{from@} @@var@{to@} [@@var@{inc@}]]) @@var@{body@}@@dots@{@} @end group @end example @noindent The function is listed in the Command and Variable Index under @samp{foobar}.@refill @node deffnx @section Two or More `First' Lines @cindex Two `First' Lines for @code{@@deffn} @cindex Grouping two definitions together @cindex Definitions grouped together @findex deffnx To create two or more `first' or header lines for a definition, follow the first @code{@@deffn} line by a line beginning with @code{@@deffnx}. The @code{@@deffnx} command works exactly like @code{@@deffn} except that it does not generate extra vertical white space between it and the preceding line.@refill @need 1000 For example, @example @group @@deffn @{Interactive Command@} isearch-forward @@deffnx @{Interactive Command@} isearch-backward These two search commands are similar except @dots{} @@end deffn @end group @end example @noindent produces @deffn {Interactive Command} isearch-forward @deffnx {Interactive Command} isearch-backward These two search commands are similar except @dots{} @end deffn Each definition command has an `x' form: @code{@@defunx}, @code{@@defvrx}, @code{@@deftypefunx}, etc. The `x' forms work similarly to @code{@@itemx} (@pxref{itemx}). @node Def Cmds in Detail @section The Definition Commands Texinfo provides more than a dozen definition commands, all of which are described in this section.@refill The definition commands automatically enter the name of the entity in the appropriate index: for example, @code{@@deffn}, @code{@@defun}, and @code{@@defmac} enter function names in the index of functions; @code{@@defvr} and @code{@@defvar} enter variable names in the index of variables.@refill Although the examples that follow mostly illustrate Lisp, the commands can be used for other programming languages.@refill @menu * Functions Commands:: Commands for functions and similar entities. * Variables Commands:: Commands for variables and similar entities. * Typed Functions:: Commands for functions in typed languages. * Typed Variables:: Commands for variables in typed languages. * Data Types:: The definition command for data types. * Abstract Objects:: Commands for object-oriented programming. @end menu @node Functions Commands @subsection Functions and Similar Entities This section describes the commands for describing functions and similar entities:@refill @table @code @findex deffn @item @@deffn @var{category} @var{name} @var{arguments}@dots{} The @code{@@deffn} command is the general definition command for functions, interactive commands, and similar entities that may take arguments. You must choose a term to describe the category of entity being defined; for example, ``Function'' could be used if the entity is a function. The @code{@@deffn} command is written at the beginning of a line and is followed on the same line by the category of entity being described, the name of this particular entity, and its arguments, if any. Terminate the definition with @code{@@end deffn} on a line of its own.@refill @need 750 For example, here is a definition: @example @group @@deffn Command forward-char nchars Move point forward @@var@{nchars@} characters. @@end deffn @end group @end example @noindent This shows a rather terse definition for a ``command'' named @code{forward-char} with one argument, @var{nchars}. @code{@@deffn} and prints argument names such as @var{nchars} in slanted type in the printed output, because we think of these names as metasyntactic variables---they stand for the actual argument values. Within the text of the description, however, write an argument name explicitly with @code{@@var} to refer to the value of the argument. In the example above, we used @samp{@@var@{nchars@}} in this way. In the unusual case when an argument name contains @samp{--}, or another character sequence which is treated specially (@pxref{Conventions}), use @code{@@var} around the argument. This causes the name to be printed in slanted typewriter, instead of the regular slanted font, exactly as input. @c except for ?` and !`, but we won't explain that. The template for @code{@@deffn} is: @example @group @@deffn @var{category} @var{name} @var{arguments}@dots{} @var{body-of-definition} @@end deffn @end group @end example @findex defun @item @@defun @var{name} @var{arguments}@dots{} The @code{@@defun} command is the definition command for functions. @code{@@defun} is equivalent to @samp{@@deffn Function @dots{}}. Terminate the definition with @code{@@end defun} on a line of its own. Thus, the template is: @example @group @@defun @var{function-name} @var{arguments}@dots{} @var{body-of-definition} @@end defun @end group @end example @findex defmac @item @@defmac @var{name} @var{arguments}@dots{} The @code{@@defmac} command is the definition command for macros. @code{@@defmac} is equivalent to @samp{@@deffn Macro @dots{}} and works like @code{@@defun}. @findex defspec @item @@defspec @var{name} @var{arguments}@dots{} The @code{@@defspec} command is the definition command for special forms. (In Lisp, a special form is an entity much like a function, @pxref{Special Forms,,, elisp, GNU Emacs Lisp Reference Manual}.) @code{@@defspec} is equivalent to @samp{@@deffn @{Special Form@} @dots{}} and works like @code{@@defun}. @end table All these commands create entries in the index of functions. @node Variables Commands @subsection Variables and Similar Entities Here are the commands for defining variables and similar entities:@refill @table @code @findex defvr @item @@defvr @var{category} @var{name} The @code{@@defvr} command is a general definition command for something like a variable---an entity that records a value. You must choose a term to describe the category of entity being defined; for example, ``Variable'' could be used if the entity is a variable. Write the @code{@@defvr} command at the beginning of a line and follow it on the same line by the category of the entity and the name of the entity. Capitalize the category name like a title. If the name of the category contains spaces, as in the name ``User Option'', enclose it in braces. Otherwise, the second word will be mistaken for the name of the entity. For example, @example @group @@defvr @{User Option@} fill-column This buffer-local variable specifies the maximum width of filled lines. @dots{} @@end defvr @end group @end example Terminate the definition with @code{@@end defvr} on a line of its own.@refill The template is: @example @group @@defvr @var{category} @var{name} @var{body-of-definition} @@end defvr @end group @end example @code{@@defvr} creates an entry in the index of variables for @var{name}. @findex defvar @item @@defvar @var{name} The @code{@@defvar} command is the definition command for variables. @code{@@defvar} is equivalent to @samp{@@defvr Variable @dots{}}.@refill @need 750 For example: @example @group @@defvar kill-ring @dots{} @@end defvar @end group @end example The template is: @example @group @@defvar @var{name} @var{body-of-definition} @@end defvar @end group @end example @code{@@defvar} creates an entry in the index of variables for @var{name}.@refill @findex defopt @item @@defopt @var{name} @cindex User options, marking The @code{@@defopt} command is the definition command for @dfn{user options}, i.e., variables intended for users to change according to taste; Emacs has many such (@pxref{Variables,,, emacs, The GNU Emacs Manual}). @code{@@defopt} is equivalent to @samp{@@defvr @{User Option@} @dots{}} and works like @code{@@defvar}. It creates an entry in the index of variables. @end table @node Typed Functions @subsection Functions in Typed Languages The @code{@@deftypefn} command and its variations are for describing functions in languages in which you must declare types of variables and functions, such as C and C++. @table @code @findex deftypefn @item @@deftypefn @var{category} @var{data-type} @var{name} @var{arguments}@dots{} The @code{@@deftypefn} command is the general definition command for functions and similar entities that may take arguments and that are typed. The @code{@@deftypefn} command is written at the beginning of a line and is followed on the same line by the category of entity being described, the type of the returned value, the name of this particular entity, and its arguments, if any.@refill @need 800 @noindent For example, @example @group @@deftypefn @{Library Function@} int foobar (int @@var@{foo@}, float @@var@{bar@}) @dots{} @@end deftypefn @end group @end example @need 1000 @noindent (where the text before the ``@dots{}'', shown above as two lines, would actually be a single line in a real Texinfo file) produces the following in Info: @smallexample @group -- Library Function: int foobar (int FOO, float BAR) @dots{} @end group @end smallexample @iftex In a printed manual, it produces: @quotation @deftypefn {Library Function} int foobar (int @var{foo}, float @var{bar}) @dots{} @end deftypefn @end quotation @end iftex This means that @code{foobar} is a ``library function'' that returns an @code{int}, and its arguments are @var{foo} (an @code{int}) and @var{bar} (a @code{float}).@refill Since in typed languages, the actual names of the arguments are typically scattered among data type names and keywords, Texinfo cannot find them without help. You can either (a)@tie{}write everything as straight text, and it will be printed in slanted type; (b)@tie{}use @code{@@var} for the variable names, which will uppercase the variable names in Info and use the slanted typewriter font in printed output; (c)@tie{}use @code{@@var} for the variable names and @code{@@code} for the type names and keywords, which will be dutifully obeyed. The template for @code{@@deftypefn} is:@refill @example @group @@deftypefn @var{category} @var{data-type} @var{name} @var{arguments} @dots{} @var{body-of-description} @@end deftypefn @end group @end example @noindent Note that if the @var{category} or @var{data type} is more than one word then it must be enclosed in braces to make it a single argument.@refill If you are describing a procedure in a language that has packages, such as Ada, you might consider using @code{@@deftypefn} in a manner somewhat contrary to the convention described in the preceding paragraphs. For example: @example @group @@deftypefn stacks private push @@ (@@var@{s@}:in out stack; @@ @@var@{n@}:in integer) @dots{} @@end deftypefn @end group @end example @noindent (The @code{@@deftypefn} arguments are shown using continuations (@pxref{Def Cmd Continuation Lines}), but could be on a single line in a real Texinfo file.) In this instance, the procedure is classified as belonging to the package @code{stacks} rather than classified as a `procedure' and its data type is described as @code{private}. (The name of the procedure is @code{push}, and its arguments are @var{s} and @var{n}.)@refill @code{@@deftypefn} creates an entry in the index of functions for @var{name}. @item @@deftypefun @var{data-type} @var{name} @var{arguments}@dots{} @findex deftypefun The @code{@@deftypefun} command is the specialized definition command for functions in typed languages. The command is equivalent to @samp{@@deftypefn Function @dots{}}. The template is: @example @group @@deftypefun @var{type} @var{name} @var{arguments}@dots{} @var{body-of-description} @@end deftypefun @end group @end example @code{@@deftypefun} creates an entry in the index of functions for @var{name}. @end table @node Typed Variables @subsection Variables in Typed Languages Variables in typed languages are handled in a manner similar to functions in typed languages. @xref{Typed Functions}. The general definition command @code{@@deftypevr} corresponds to @code{@@deftypefn} and the specialized definition command @code{@@deftypevar} corresponds to @code{@@deftypefun}.@refill @table @code @findex deftypevr @item @@deftypevr @var{category} @var{data-type} @var{name} The @code{@@deftypevr} command is the general definition command for something like a variable in a typed language---an entity that records a value. You must choose a term to describe the category of the entity being defined; for example, ``Variable'' could be used if the entity is a variable.@refill The @code{@@deftypevr} command is written at the beginning of a line and is followed on the same line by the category of the entity being described, the data type, and the name of this particular entity.@refill @need 800 @noindent For example: @example @group @@deftypevr @{Global Flag@} int enable @dots{} @@end deftypevr @end group @end example @noindent produces the following in Info: @example @group -- Global Flag: int enable @dots{} @end group @end example @iftex @noindent and the following in a printed manual: @quotation @deftypevr {Global Flag} int enable @dots{} @end deftypevr @end quotation @end iftex @need 800 The template is: @example @@deftypevr @var{category} @var{data-type} @var{name} @var{body-of-description} @@end deftypevr @end example @findex deftypevar @item @@deftypevar @var{data-type} @var{name} The @code{@@deftypevar} command is the specialized definition command for variables in typed languages. @code{@@deftypevar} is equivalent to @samp{@@deftypevr Variable @dots{}}. The template is: @example @group @@deftypevar @var{data-type} @var{name} @var{body-of-description} @@end deftypevar @end group @end example @end table These commands create entries in the index of variables. @node Data Types @subsection Data Types Here is the command for data types:@refill @table @code @findex deftp @item @@deftp @var{category} @var{name} @var{attributes}@dots{} The @code{@@deftp} command is the generic definition command for data types. The command is written at the beginning of a line and is followed on the same line by the category, by the name of the type (which is a word like @code{int} or @code{float}), and then by names of attributes of objects of that type. Thus, you could use this command for describing @code{int} or @code{float}, in which case you could use @code{data type} as the category. (A data type is a category of certain objects for purposes of deciding which operations can be performed on them.)@refill In Lisp, for example, @dfn{pair} names a particular data type, and an object of that type has two slots called the @sc{car} and the @sc{cdr}. Here is how you would write the first line of a definition of @code{pair}.@refill @example @group @@deftp @{Data type@} pair car cdr @dots{} @@end deftp @end group @end example @need 950 The template is: @example @group @@deftp @var{category} @var{name-of-type} @var{attributes}@dots{} @var{body-of-definition} @@end deftp @end group @end example @code{@@deftp} creates an entry in the index of data types. @end table @node Abstract Objects @subsection Object-Oriented Programming @cindex Object-oriented programming Here are the commands for formatting descriptions about abstract objects, such as are used in object-oriented programming. A class is a defined type of abstract object. An instance of a class is a particular object that has the type of the class. An instance variable is a variable that belongs to the class but for which each instance has its own value. @menu * Variables: Object-Oriented Variables. * Methods: Object-Oriented Methods. @end menu @node Object-Oriented Variables @subsubsection Object-Oriented Variables @cindex Variables, object-oriented These commands allow you to define different sorts of variables in object-oriented programming languages. @table @code @item @@defcv @var{category} @var{class} @var{name} @findex defcv The @code{@@defcv} command is the general definition command for variables associated with classes in object-oriented programming. The @code{@@defcv} command is followed by three arguments: the category of thing being defined, the class to which it belongs, and its name. For instance: @example @group @@defcv @{Class Option@} Window border-pattern @dots{} @@end defcv @end group @end example @noindent produces: @defcv {Class Option} Window border-pattern @dots{} @end defcv @code{@@defcv} creates an entry in the index of variables. @item @@deftypecv @var{category} @var{class} @var{data-type} @var{name} @findex deftypecv The @code{@@deftypecv} command is the definition command for typed class variables in object-oriented programming. It is analogous to @code{@@defcv} with the addition of the @var{data-type} parameter to specify the type of the instance variable. Ordinarily, the data type is a programming language construct that should be marked with @code{@@code}. For instance: @example @group @@deftypecv @{Class Option@} Window @@code@{int@} border-pattern @dots{} @@end deftypecv @end group @end example @noindent produces: @deftypecv {Class Option} Window @code{int} border-pattern @dots{} @end deftypecv @code{@@deftypecv} creates an entry in the index of variables. @item @@defivar @var{class} @var{name} @findex defivar The @code{@@defivar} command is the definition command for instance variables in object-oriented programming. @code{@@defivar} is equivalent to @samp{@@defcv @{Instance Variable@} @dots{}}. For instance: @example @group @@defivar Window border-pattern @dots{} @@end defivar @end group @end example @noindent produces: @defivar Window border-pattern @dots{} @end defivar @code{@@defivar} creates an entry in the index of variables. @item @@deftypeivar @var{class} @var{data-type} @var{name} @findex deftypeivar The @code{@@deftypeivar} command is the definition command for typed instance variables in object-oriented programming. It is analogous to @code{@@defivar} with the addition of the @var{data-type} parameter to specify the type of the instance variable. Ordinarily, the data type is a programming language construct that should be marked with @code{@@code}. For instance: @example @group @@deftypeivar Window @@code@{int@} border-pattern @dots{} @@end deftypeivar @end group @end example @noindent produces: @deftypeivar Window @code{int} border-pattern @dots{} @end deftypeivar @code{@@deftypeivar} creates an entry in the index of variables. @end table @node Object-Oriented Methods @subsubsection Object-Oriented Methods @cindex Methods, object-oriented These commands allow you to define different sorts of function-like entities resembling methods in object-oriented programming languages. These entities take arguments, as functions do, but are associated with particular classes of objects. @table @code @findex defop @item @@defop @var{category} @var{class} @var{name} @var{arguments}@dots{} The @code{@@defop} command is the general definition command for these method-like entities. For example, some systems have constructs called @dfn{wrappers} that are associated with classes as methods are, but that act more like macros than like functions. You could use @code{@@defop Wrapper} to describe one of these.@refill Sometimes it is useful to distinguish methods and @dfn{operations}. You can think of an operation as the specification for a method. Thus, a window system might specify that all window classes have a method named @code{expose}; we would say that this window system defines an @code{expose} operation on windows in general. Typically, the operation has a name and also specifies the pattern of arguments; all methods that implement the operation must accept the same arguments, since applications that use the operation do so without knowing which method will implement it.@refill Often it makes more sense to document operations than methods. For example, window application developers need to know about the @code{expose} operation, but need not be concerned with whether a given class of windows has its own method to implement this operation. To describe this operation, you would write:@refill @example @@defop Operation windows expose @end example The @code{@@defop} command is written at the beginning of a line and is followed on the same line by the overall name of the category of operation, the name of the class of the operation, the name of the operation, and its arguments, if any.@refill The template is: @example @group @@defop @var{category} @var{class} @var{name} @var{arguments}@dots{} @var{body-of-definition} @@end defop @end group @end example @code{@@defop} creates an entry, such as `@code{expose} on @code{windows}', in the index of functions.@refill @findex deftypeop @item @@deftypeop @var{category} @var{class} @var{data-type} @var{name} @var{arguments}@dots{} The @code{@@deftypeop} command is the definition command for typed operations in object-oriented programming. It is similar to @code{@@defop} with the addition of the @var{data-type} parameter to specify the return type of the method. @code{@@deftypeop} creates an entry in the index of functions. @item @@defmethod @var{class} @var{name} @var{arguments}@dots{} @findex defmethod The @code{@@defmethod} command is the definition command for methods in object-oriented programming. A method is a kind of function that implements an operation for a particular class of objects and its subclasses. @ignore @c ADR: Who cares?!? @c KB: Oh, I don't know, I think this info is crucial! In the Lisp Machine, methods actually were functions, but they were usually defined with @code{defmethod}. @end ignore @code{@@defmethod} is equivalent to @samp{@@defop Method @dots{}}. The command is written at the beginning of a line and is followed by the name of the class of the method, the name of the method, and its arguments, if any.@refill @noindent For example: @example @group @@defmethod @code{bar-class} bar-method argument @dots{} @@end defmethod @end group @end example @noindent illustrates the definition for a method called @code{bar-method} of the class @code{bar-class}. The method takes an argument. @code{@@defmethod} creates an entry in the index of functions. @item @@deftypemethod @var{class} @var{data-type} @var{name} @var{arguments}@dots{} @findex defmethod The @code{@@deftypemethod} command is the definition command for methods in object-oriented typed languages, such as C++ and Java. It is similar to the @code{@@defmethod} command with the addition of the @var{data-type} parameter to specify the return type of the method. @code{@@deftypemethod} creates an entry in the index of functions. @end table @node Def Cmd Conventions @section Conventions for Writing Definitions @cindex Definition conventions @cindex Conventions for writing definitions When you write a definition using @code{@@deffn}, @code{@@defun}, or one of the other definition commands, please take care to use arguments that indicate the meaning, as with the @var{count} argument to the @code{forward-word} function. Also, if the name of an argument contains the name of a type, such as @var{integer}, take care that the argument actually is of that type.@refill @node Sample Function Definition @section A Sample Function Definition @cindex Function definitions @cindex Command definitions @cindex Macro definitions @cindex Sample function definition A function definition uses the @code{@@defun} and @code{@@end defun} commands. The name of the function follows immediately after the @code{@@defun} command and it is followed, on the same line, by the parameter list.@refill Here is a definition from @ref{Calling Functions,,, elisp, The GNU Emacs Lisp Reference Manual}. @quotation @defun apply function &rest arguments @code{apply} calls @var{function} with @var{arguments}, just like @code{funcall} but with one difference: the last of @var{arguments} is a list of arguments to give to @var{function}, rather than a single argument. We also say that this list is @dfn{appended} to the other arguments. @code{apply} returns the result of calling @var{function}. As with @code{funcall}, @var{function} must either be a Lisp function or a primitive function; special forms and macros do not make sense in @code{apply}. @example (setq f 'list) @result{} list (apply f 'x 'y 'z) @error{} Wrong type argument: listp, z (apply '+ 1 2 '(3 4)) @result{} 10 (apply '+ '(1 2 3 4)) @result{} 10 (apply 'append '((a b c) nil (x y z) nil)) @result{} (a b c x y z) @end example An interesting example of using @code{apply} is found in the description of @code{mapcar}.@refill @end defun @end quotation @need 1200 In the Texinfo source file, this example looks like this: @example @group @@defun apply function &rest arguments @@code@{apply@} calls @@var@{function@} with @@var@{arguments@}, just like @@code@{funcall@} but with one difference: the last of @@var@{arguments@} is a list of arguments to give to @@var@{function@}, rather than a single argument. We also say that this list is @@dfn@{appended@} to the other arguments. @end group @group @@code@{apply@} returns the result of calling @@var@{function@}. As with @@code@{funcall@}, @@var@{function@} must either be a Lisp function or a primitive function; special forms and macros do not make sense in @@code@{apply@}. @end group @group @@example (setq f 'list) @@result@{@} list (apply f 'x 'y 'z) @@error@{@} Wrong type argument: listp, z (apply '+ 1 2 '(3 4)) @@result@{@} 10 (apply '+ '(1 2 3 4)) @@result@{@} 10 (apply 'append '((a b c) nil (x y z) nil)) @@result@{@} (a b c x y z) @@end example @end group @group An interesting example of using @@code@{apply@} is found in the description of @@code@{mapcar@}. @@end defun @end group @end example @noindent In this manual, this function is listed in the Command and Variable Index under @code{apply}.@refill Ordinary variables and user options are described using a format like that for functions except that variables do not take arguments. @node Conditionals @chapter Conditionally Visible Text @cindex Conditionally visible text @cindex Text, conditionally visible @cindex Visibility of conditional text @cindex If text conditionally visible The @dfn{conditional commands} allow you to use different text for different output formats, or for general conditions that you define. For example, you can use them to specify different text for the printed manual and the Info output. The conditional commands comprise the following categories. @itemize @bullet @item Commands specific to an output format (Info, @TeX{}, HTML, @dots{}). @item Commands specific to any output format @emph{other} than a given one (not Info, not @TeX{}, @dots{}). @item `Raw' formatter text for any output format, passed straight through with no interpretation of @@-commands. @item Format-independent variable substitutions, and testing if a variable is set or clear. @end itemize @menu * Conditional Commands:: Text for a given format. * Conditional Not Commands:: Text for any format other than a given one. * Raw Formatter Commands:: Using raw formatter commands. * set clear value:: Variable tests and substitutions. * Conditional Nesting:: Using conditionals inside conditionals. @end menu @node Conditional Commands @section Conditional Commands Texinfo has an @code{@@if@var{format}} environment for each output format, to allow conditional inclusion of text for a particular output format. @findex ifinfo @code{@@ifinfo} begins segments of text that should be ignored by @TeX{} when it typesets the printed manual, and by @command{makeinfo} when not producing Info output. The segment of text appears only in the Info file and, for historical compatibility, the plain text output. @findex ifdocbook @findex ifhtml @findex ifplaintext @findex iftex @findex ifxml The environments for the other formats are analogous: @table @code @item @@ifdocbook @dots{} @@end ifdocbook Text to appear only in the Docbook output. @item @@ifhtml @dots{} @@end ifhtml Text to appear only in the HTML output. @item @@ifplaintext @dots{} @@end ifplaintext Text to appear only in the plain text output. @item @@iftex @dots{} @@end iftex Text to appear only in the printed manual. @item @@ifxml @dots{} @@end ifxml Text to appear only in the XML output. @end table The @code{@@if@dots{}} and @code{@@end if@dots{}} commands must appear on lines by themselves in your source file. Here is an example showing all these conditionals: @example @@iftex This text will appear only in the printed manual. @@end iftex @@ifinfo However, this text will appear only in Info and plain text. @@end ifinfo @@ifhtml And this text will only appear in HTML. @@end ifhtml @@ifplaintext Whereas this text will only appear in plain text. @@end ifplaintext @@ifxml Notwithstanding that this will only appear in XML. @@end ifxml @@ifdocbook Nevertheless, this will only appear in Docbook. @@end ifdocbook @end example @noindent The preceding example produces the following line: @iftex This text will appear only in the printed manual. @end iftex @ifinfo However, this text will appear only in Info and plain text. @end ifinfo @ifhtml And this text will only appear in HTML. @end ifhtml @ifplaintext Whereas this text will only appear in plain text. @end ifplaintext @ifxml Notwithstanding that this will only appear in XML. @end ifxml @ifdocbook Nevertheless, this will only appear in Docbook. @end ifdocbook @noindent Notice that you only see one of the input lines, depending on which version of the manual you are reading. @node Conditional Not Commands @section Conditional Not Commands @findex ifnotdocbook @findex ifnothtml @findex ifnotinfo @findex ifnotplaintext @findex ifnottex @findex ifnotxml You can specify text to be included in any output format @emph{other} than a given one with the @code{@@ifnot@dots{}} environments: @example @@ifnotdocbook @dots{} @@end ifnotdocbook @@ifnothtml @dots{} @@end ifnothtml @@ifnotinfo @dots{} @@end ifnotinfo @@ifnotplaintext @dots{} @@end ifnotplaintext @@ifnottex @dots{} @@end ifnottex @@ifnotxml @dots{} @@end ifnotxml @end example @noindent The @code{@@ifnot@dots{}} command and the @code{@@end} command must appear on lines by themselves in your actual source file. If the output file is being made in the given format, the region is @emph{ignored}. Otherwise, it is included. There is one exception (for historical compatibility): @code{@@ifnotinfo} text is omitted for both Info and plain text output, not just Info. To specify text which appears only in Info and not in plain text, use @code{@@ifnotplaintext}, like this: @example @@ifinfo @@ifnotplaintext This will be in Info, but not plain text. @@end ifnotplaintext @@end ifinfo @end example The regions delimited by these commands are ordinary Texinfo source as with @code{@@iftex}, not raw formatter source as with @code{@@tex} (@pxref{Raw Formatter Commands}). @node Raw Formatter Commands @section Raw Formatter Commands @cindex Raw formatter commands @cindex @TeX{} commands, using ordinary @cindex Ordinary @TeX{} commands, using @cindex Commands using raw @TeX{} @cindex Docbook, including raw @cindex HTML, including raw @cindex XML, including raw @cindex Plain @TeX{} Inside a region delineated by @code{@@iftex} and @code{@@end iftex}, you can embed some raw @TeX{} commands. The Texinfo processors will ignore such a region unless @TeX{} output is being produced. You can write the @TeX{} commands as you would write them in a normal @TeX{} file, except that you must replace the @samp{\} used by @TeX{} with an @samp{@@}. For example, in the @code{@@titlepage} section of a Texinfo file, you can use the @TeX{} command @code{@@vskip} to format the copyright page. (The @code{@@titlepage} command causes Info to ignore the region automatically, as it does with the @code{@@iftex} command.) However, most features of plain @TeX{} will not work within @code{@@iftex}, as they are overridden by Texinfo features. The purpose of @code{@@iftex} is to provide conditional processing for the Texinfo source, not provide access to underlying formatting features. @findex tex You can enter plain @TeX{} completely, and use @samp{\} in the @TeX{} commands, by delineating a region with the @code{@@tex} and @code{@@end tex} commands. All plain @TeX{} commands and category codes are restored within an @code{@@tex} region. The sole exception is that the @code{@@} character still introduces a command, so that @code{@@end tex} can be recognized properly. As with @code{@@iftex}, Texinfo processors will ignore such a region unless @TeX{} output is being produced. @findex \gdef @r{within @code{@@tex}} In complex cases, you may wish to define new @TeX{} macros within @code{@@tex}. You must use @code{\gdef} to do this, not @code{\def}, because @code{@@tex} regions are processed in a @TeX{} group. @cindex Mathematical expressions As an example, here is a mathematical expression written in plain @TeX{}: @example @@tex $$ \chi^2 = \sum_@{i=1@}^N \left (y_i - (a + b x_i) \over \sigma_i\right)^2 $$ @@end tex @end example @noindent The output of this example will appear only in a printed manual. If you are reading this in Info, you will not see the equation that appears in the printed manual. @iftex In a printed manual, the above expression looks like this: @end iftex @tex $$ \chi^2 = \sum_{i=1}^N \left(y_i - (a + b x_i) \over \sigma_i\right)^2 $$ @end tex @findex ifhtml @findex html Analogously, you can use @code{@@ifhtml @dots{} @@end ifhtml} to delimit a region to be included in HTML output only, and @code{@@html @dots{} @@end html} for a region of raw HTML. @findex ifxml @findex xml Likewise, you can use @code{@@ifxml @dots{} @@end ifxml} to delimit a region to be included in XML output only, and @code{@@xml @dots{} @@end xml} for a region of raw XML. @findex ifdocbook @findex docbook Again likewise, you can use @code{@@ifdocbook @dots{} @@end ifdocbook} to delimit a region to be included in Docbook output only, and @code{@@docbook @dots{} @@end docbook} for a region of raw Docbook. In all cases, the exception to the raw processing is that @code{@@} is still an escape character, so the @code{@@end} command can be recognized. @node set clear value @section @code{@@set}, @code{@@clear}, and @code{@@value} You can direct the Texinfo formatting commands to format or ignore parts of a Texinfo file with the @code{@@set}, @code{@@clear}, @code{@@ifset}, and @code{@@ifclear} commands. Here are brief descriptions of these commands, see the following sections for more details: @table @code @item @@set @var{flag} [@var{value}] Set the variable @var{flag}, to the optional @var{value} if specified. @item @@clear @var{flag} Undefine the variable @var{flag}, whether or not it was previously defined. @item @@ifset @var{flag} If @var{flag} is set, text through the next @code{@@end ifset} command is formatted. If @var{flag} is clear, text through the following @code{@@end ifset} command is ignored. @item @@ifclear @var{flag} If @var{flag} is set, text through the next @code{@@end ifclear} command is ignored. If @var{flag} is clear, text through the following @code{@@end ifclear} command is formatted. @end table @menu * set value:: Expand a flag variable to a string. * ifset ifclear:: Format a region if a flag is set. * value Example:: An easy way to update edition information. @end menu @node set value @subsection @code{@@set} and @code{@@value} @findex value You use the @code{@@set} command to specify a value for a flag, which is later expanded by the @code{@@value} command. A @dfn{flag} (aka @dfn{variable}) is an identifier. It is best to use only letters and numerals in a flag name, not @samp{-} or @samp{_}---they will work in some contexts, but not all, due to limitations in @TeX{}. The value is the remainder of the input line, and can contain anything. Write the @code{@@set} command like this: @example @@set foo This is a string. @end example @noindent This sets the value of the flag @code{foo} to ``This is a string.''. The Texinfo formatters then replace an @code{@@value@{@var{flag}@}} command with the string to which @var{flag} is set. Thus, when @code{foo} is set as shown above, the Texinfo formatters convert this: @example @group @@value@{foo@} @exdent @r{to this:} This is a string. @end group @end example You can write an @code{@@value} command within a paragraph; but you must write an @code{@@set} command on a line of its own. If you write the @code{@@set} command like this: @example @@set foo @end example @noindent without specifying a string, the value of @code{foo} is the empty string. If you clear a previously set flag with @code{@@clear @var{flag}}, a subsequent @code{@@value@{flag@}} command will report an error. For example, if you set @code{foo} as follows: @example @@set howmuch very, very, very @end example @noindent then the formatters transform @example @group It is a @@value@{howmuch@} wet day. @exdent @r{into} It is a very, very, very wet day. @end group @end example If you write @example @@clear howmuch @end example @noindent then the formatters transform @example @group It is a @@value@{howmuch@} wet day. @exdent @r{into} It is a @{No value for "howmuch"@} wet day. @end group @end example @node ifset ifclear @subsection @code{@@ifset} and @code{@@ifclear} @findex ifset When a @var{flag} is set, the Texinfo formatting commands format text between subsequent pairs of @code{@@ifset @var{flag}} and @code{@@end ifset} commands. When the @var{flag} is cleared, the Texinfo formatting commands do @emph{not} format the text. @code{@@ifclear} operates analogously. Write the conditionally formatted text between @code{@@ifset @var{flag}} and @code{@@end ifset} commands, like this: @example @group @@ifset @var{flag} @var{conditional-text} @@end ifset @end group @end example For example, you can create one document that has two variants, such as a manual for a `large' and `small' model: @cindex Shrubbery @example You can use this machine to dig up shrubs without hurting them. @@set large @@ifset large It can also dig up fully grown trees. @@end ifset Remember to replant promptly @dots{} @end example @noindent In the example, the formatting commands will format the text between @code{@@ifset large} and @code{@@end ifset} because the @code{large} flag is set. When @var{flag} is cleared, the Texinfo formatting commands do @emph{not} format the text between @code{@@ifset @var{flag}} and @code{@@end ifset}; that text is ignored and does not appear in either printed or Info output. For example, if you clear the flag of the preceding example by writing an @code{@@clear large} command after the @code{@@set large} command (but before the conditional text), then the Texinfo formatting commands ignore the text between the @code{@@ifset large} and @code{@@end ifset} commands. In the formatted output, that text does not appear; in both printed and Info output, you see only the lines that say, ``You can use this machine to dig up shrubs without hurting them. Remember to replant promptly @dots{}''. @findex ifclear If a flag is cleared with an @code{@@clear @var{flag}} command, then the formatting commands format text between subsequent pairs of @code{@@ifclear} and @code{@@end ifclear} commands. But if the flag is set with @code{@@set @var{flag}}, then the formatting commands do @emph{not} format text between an @code{@@ifclear} and an @code{@@end ifclear} command; rather, they ignore that text. An @code{@@ifclear} command looks like this: @example @@ifclear @var{flag} @end example @node value Example @subsection @code{@@value} Example You can use the @code{@@value} command to minimize the number of places you need to change when you record an update to a manual. @xref{GNU Sample Texts}, for the full text of an example of using this to work with Automake distributions. This example is adapted from @ref{Top,, Overview, make, The GNU Make Manual}. @enumerate @item Set the flags: @example @group @@set EDITION 0.35 Beta @@set VERSION 3.63 Beta @@set UPDATED 14 August 1992 @@set UPDATE-MONTH August 1992 @end group @end example @item Write text for the @code{@@copying} section (@pxref{copying}): @example @group @@copying This is Edition @@value@{EDITION@}, last updated @@value@{UPDATED@}, of @@cite@{The GNU Make Manual@}, for @@code@{make@}, version @@value@{VERSION@}. Copyright @dots{} Permission is granted @dots{} @@end copying @end group @end example @item Write text for the title page, for people reading the printed manual: @example @group @@titlepage @@title GNU Make @@subtitle A Program for Directing Recompilation @@subtitle Edition @@value@{EDITION@}, @dots{} @@subtitle @@value@{UPDATE-MONTH@} @@page @@insertcopying @dots{} @@end titlepage @end group @end example @noindent (On a printed cover, a date listing the month and the year looks less fussy than a date listing the day as well as the month and year.) @item Write text for the Top node, for people reading the Info file: @example @group @@ifnottex @@node Top @@top Make @@insertcopying @dots{} @@end ifnottex @end group @end example After you format the manual, the @code{@@value} constructs have been expanded, so the output contains text like this: @example @group This is Edition 0.35 Beta, last updated 14 August 1992, of `The GNU Make Manual', for `make', Version 3.63 Beta. @end group @end example @end enumerate When you update the manual, you change only the values of the flags; you do not need to edit the three sections. @node Conditional Nesting @section Conditional Nesting @cindex Conditionals, nested @cindex Nesting conditionals Conditionals can be nested; however, the details are a little tricky. The difficulty comes with failing conditionals, such as @code{@@ifhtml} when HTML is not being produced, where the included text is to be ignored. However, it is not to be @emph{completely} ignored, since it is useful to have one @code{@@ifset} inside another, for example---that is a way to include text only if two conditions are met. Here's an example: @example @@ifset somevar @@ifset anothervar Both somevar and anothervar are set. @@end ifset @@ifclear anothervar Somevar is set, anothervar is not. @@end ifclear @@end ifset @end example Technically, Texinfo requires that for a failing conditional, the ignored text must be properly nested with respect to that failing conditional. Unfortunately, it's not always feasible to check that @emph{all} conditionals are properly nested, because then the processors could have to fully interpret the ignored text, which defeats the purpose of the command. Here's an example illustrating these rules: @example @@ifset a @@ifset b @@ifclear ok - ok, ignored @@end junky - ok, ignored @@end ifset @@c WRONG - missing @@end ifset. @end example Finally, as mentioned above, all conditional commands must be on lines by themselves, with no text (even spaces) before or after. Otherwise, the processors cannot reliably determine which commands to consider for nesting purposes. @node Internationalization @chapter Internationalization @cindex Internationalization Texinfo has some support for writing in languages other than English, although this area still needs considerable work. For a list of the various accented and special characters Texinfo supports, see @ref{Inserting Accents}. @menu * documentlanguage:: Declaring the current language. * documentencoding:: Declaring the input encoding. @end menu @node documentlanguage @section @code{@@documentlanguage @var{cc}}: Set the Document Language @findex documentlanguage @cindex Language, declaring @cindex Document language, declaring The @code{@@documentlanguage} command declares the current document language. Write it on a line by itself, with a two-letter ISO-639 language code following (list is included below). If you have a multilingual document, the intent is to be able to use this command multiple times, to declare each language change. If the command is not used at all, the default is @code{en} for English. @cindex @file{txi-@var{cc}.tex} At present, this command is ignored in Info and HTML output. For @TeX{}, it causes the file @file{txi-@var{cc}.tex} to be read (if it exists). Such a file appropriately redefines the various English words used in @TeX{} output, such as `Chapter', `See', and so on. @cindex Hyphenation patterns, language-dependent It would be good if this command also changed @TeX{}'s ideas of the current hyphenation patterns (via the @TeX{} primitive @code{\language}), but this is unfortunately not currently implemented. @cindex ISO 639 codes @cindex Language codes Hereare the valid language codes, from ISO-639. @multitable @columnfractions .07 .26 .07 .26 .07 .26 @item @code{aa} @tab Afar @tab @code{ab} @tab Abkhazian @tab @code{af} @tab Afrikaans @item @code{am} @tab Amharic @tab @code{ar} @tab Arabic @tab @code{as} @tab Assamese @item @code{ay} @tab Aymara @tab @code{az} @tab Azerbaijani @tab @code{ba} @tab Bashkir @item @code{be} @tab Byelorussian @tab @code{bg} @tab Bulgarian @tab @code{bh} @tab Bihari @item @code{bi} @tab Bislama @tab @code{bn} @tab Bengali; Bangla @tab @code{bo} @tab Tibetan @item @code{br} @tab Breton @tab @code{ca} @tab Catalan @tab @code{co} @tab Corsican @item @code{cs} @tab Czech @tab @code{cy} @tab Welsh @tab @code{da} @tab Danish @item @code{de} @tab German @tab @code{dz} @tab Bhutani @tab @code{el} @tab Greek @item @code{en} @tab English @tab @code{eo} @tab Esperanto @tab @code{es} @tab Spanish @item @code{et} @tab Estonian @tab @code{eu} @tab Basque @tab @code{fa} @tab Persian @item @code{fi} @tab Finnish @tab @code{fj} @tab Fiji @tab @code{fo} @tab Faroese @item @code{fr} @tab French @tab @code{fy} @tab Frisian @tab @code{ga} @tab Irish @item @code{gd} @tab Scots Gaelic @tab @code{gl} @tab Galician @tab @code{gn} @tab Guarani @item @code{gu} @tab Gujarati @tab @code{ha} @tab Hausa @tab @code{he} @tab Hebrew @item @code{hi} @tab Hindi @tab @code{hr} @tab Croatian @tab @code{hu} @tab Hungarian @item @code{hy} @tab Armenian @tab @code{ia} @tab Interlingua @tab @code{id} @tab Indonesian @item @code{ie} @tab Interlingue @tab @code{ik} @tab Inupiak @tab @code{is} @tab Icelandic @item @code{it} @tab Italian @tab @code{iu} @tab Inuktitut @tab @code{ja} @tab Japanese @item @code{jw} @tab Javanese @tab @code{ka} @tab Georgian @tab @code{kk} @tab Kazakh @item @code{kl} @tab Greenlandic @tab @code{km} @tab Cambodian @tab @code{kn} @tab Kannada @item @code{ks} @tab Kashmiri @tab @code{ko} @tab Korean @tab @code{ku} @tab Kurdish @item @code{ky} @tab Kirghiz @tab @code{la} @tab Latin @tab @code{ln} @tab Lingala @item @code{lt} @tab Lithuanian @tab @code{lo} @tab Laothian @tab @code{lv} @tab Latvian, Lettish @item @code{mg} @tab Malagasy @tab @code{mi} @tab Maori @tab @code{mk} @tab Macedonian @item @code{ml} @tab Malayalam @tab @code{mn} @tab Mongolian @tab @code{mo} @tab Moldavian @item @code{mr} @tab Marathi @tab @code{ms} @tab Malay @tab @code{mt} @tab Maltese @item @code{my} @tab Burmese @tab @code{na} @tab Nauru @tab @code{ne} @tab Nepali @item @code{nl} @tab Dutch @tab @code{no} @tab Norwegian @tab @code{oc} @tab Occitan @item @code{om} @tab (Afan) Oromo @tab @code{or} @tab Oriya @tab @code{pa} @tab Punjabi @item @code{pl} @tab Polish @tab @code{ps} @tab Pashto, Pushto @tab @code{pt} @tab Portuguese @item @code{qu} @tab Quechua @tab @code{rm} @tab Rhaeto-Romance @tab @code{rn} @tab Kirundi @item @code{ro} @tab Romanian @tab @code{ru} @tab Russian @tab @code{rw} @tab Kinyarwanda @item @code{sa} @tab Sanskrit @tab @code{sd} @tab Sindhi @tab @code{sg} @tab Sangro @item @code{sh} @tab Serbo-Croatian @tab @code{si} @tab Sinhalese @tab @code{sk} @tab Slovak @item @code{sl} @tab Slovenian @tab @code{sm} @tab Samoan @tab @code{sn} @tab Shona @item @code{so} @tab Somali @tab @code{sq} @tab Albanian @tab @code{sr} @tab Serbian @item @code{ss} @tab Siswati @tab @code{st} @tab Sesotho @tab @code{su} @tab Sundanese @item @code{sv} @tab Swedish @tab @code{sw} @tab Swahili @tab @code{ta} @tab Tamil @item @code{te} @tab Telugu @tab @code{tg} @tab Tajik @tab @code{th} @tab Thai @item @code{ti} @tab Tigrinya @tab @code{tk} @tab Turkmen @tab @code{tl} @tab Tagalog @item @code{tn} @tab Setswana @tab @code{to} @tab Tonga @tab @code{tr} @tab Turkish @item @code{ts} @tab Tsonga @tab @code{tt} @tab Tatar @tab @code{tw} @tab Twi @item @code{ug} @tab Uighur @tab @code{uk} @tab Ukrainian @tab @code{ur} @tab Urdu @item @code{uz} @tab Uzbek @tab @code{vi} @tab Vietnamese @tab @code{vo} @tab Volapuk @item @code{wo} @tab Wolof @tab @code{xh} @tab Xhosa @tab @code{yi} @tab Yiddish @item @code{yo} @tab Yoruba @tab @code{za} @tab Zhuang @tab @code{zh} @tab Chinese @item @code{zu} @tab Zulu @end multitable @node documentencoding @section @code{@@documentencoding @var{enc}}: Set Input Encoding @findex documentencoding @cindex Encoding, declaring @cindex Input encoding, declaring @cindex Character set, declaring @cindex Document input encoding The @code{@@documentencoding} command declares the input document encoding. Write it on a line by itself, with a valid encoding specification following. At present, Texinfo supports only these encodings: @table @code @item US-ASCII This has no particular effect, but it's included for completeness. @itemx ISO-8859-1 @itemx ISO-8859-15 @item ISO-8859-2 These specify the standard encodings for Western European (the first two) and Eastern European languages (the third), respectively. ISO 8859-15 replaces some little-used characters from 8859-1 (e.g., precomposed fractions) with more commonly needed ones, such as the Euro symbol. A full description of the encodings is beyond our scope here; one useful reference is @uref{http://czyborra.com/charsets/iso8859.html}. @end table Specifying an encoding @var{enc} has the following effects: @opindex --enable-encoding @cindex Local Variables: section, for encoding @cindex Info output, and encoding In Info output, if the option @option{--enable-encoding} is given to @command{makeinfo}, a so-called `Local Variables' section (@pxref{File Variables,,,emacs,The GNU Emacs Manual}) is output including @var{enc}. This allows Info readers to set the encoding appropriately. @example Local Variables: coding: @var{enc} End: @end example @cindex HTML output, and encodings @cindex @code{http-equiv}, and charset specification @cindex @code{<meta>} HTML tag, and charset specification In HTML output, a @samp{<meta>} tag is output, in the @samp{<head>} section of the HTML, that specifies @var{enc}. Web servers and browsers cooperate to use this information so the correct encoding is used to display the page, if supported by the system. @example <meta http-equiv="Content-Type" content="text/html; charset=@var{enc}"> @end example In all other cases, it is recognized but ignored. @node Defining New Texinfo Commands @chapter Defining New Texinfo Commands @cindex Macros @cindex Defining new Texinfo commands @cindex New Texinfo commands, defining @cindex Texinfo commands, defining new @cindex User-defined Texinfo commands Texinfo provides several ways to define new commands: @itemize @bullet @item A Texinfo @dfn{macro} allows you to define a new Texinfo command as any sequence of text and/or existing commands (including other macros). The macro can have any number of @dfn{parameters}---text you supply each time you use the macro. Incidentally, these macros have nothing to do with the @code{@@defmac} command, which is for documenting macros in the subject of the manual (@pxref{Def Cmd Template}). @item @samp{@@alias} is a convenient way to define a new name for an existing command. @item @samp{@@definfoenclose} allows you to define new commands with customized output in the Info file. @end itemize @menu * Defining Macros:: Defining and undefining new commands. * Invoking Macros:: Using a macro, once you've defined it. * Macro Details:: Limitations of Texinfo macros. * alias:: Command aliases. * definfoenclose:: Customized highlighting. @end menu @node Defining Macros @section Defining Macros @cindex Defining macros @cindex Macro definitions @findex macro You use the Texinfo @code{@@macro} command to define a macro, like this: @example @@macro @var{macroname}@{@var{param1}, @var{param2}, @dots{}@} @var{text} @dots{} \@var{param1}\ @dots{} @@end macro @end example The @dfn{parameters} @var{param1}, @var{param2}, @dots{} correspond to arguments supplied when the macro is subsequently used in the document (described in the next section). @cindex Macro names, valid characters in @cindex Names of macros, valid characters of For a macro to work consistently with @TeX{}, @var{macroname} must consist entirely of letters: no digits, hyphens, underscores, or other special characters. So, we recommend using only letters. However, @command{makeinfo} will accept anything except @samp{@{@}_^=}; @samp{_} and @samp{^} are excluded so that macros can be called in @code{@@math} mode without a following space (@pxref{math,,@code{@@math}}). If a macro needs no parameters, you can define it either with an empty list (@samp{@@macro foo @{@}}) or with no braces at all (@samp{@@macro foo}). @cindex Body of a macro @cindex Mutually recursive macros @cindex Recursion, mutual The definition or @dfn{body} of the macro can contain most Texinfo commands, including previously-defined macros. Not-yet-defined macro invocations are not allowed; thus, it is not possible to have mutually recursive Texinfo macros. Also, a macro definition that defines another macro does not work in @TeX{} due to limitations in the design of @code{@@macro}. @cindex Parameters to macros In the macro body, instances of a parameter name surrounded by backslashes, as in @samp{\@var{param1}\} in the example above, are replaced by the corresponding argument from the macro invocation. You can use parameter names any number of times in the body, including zero. @cindex Backslash in macros To get a single @samp{\} in the macro expansion, use @samp{\\}. Any other use of @samp{\} in the body yields a warning. @cindex Spaces in macros @cindex Whitespace in macros The newlines after the @code{@@macro} line and before the @code{@@end macro} line are ignored, that is, not included in the macro body. All other whitespace is treated according to the usual Texinfo rules. @cindex Recursive macro invocations @findex rmacro To allow a macro to be used recursively, that is, in an argument to a call to itself, you must define it with @samp{@@rmacro}, like this: @example @@rmacro rmac @{arg@} a\arg\b @@end rmacro @dots{} @@rmac@{1@@rmac@{text@}2@} @end example This produces the output `a1atextb2b'. With @samp{@@macro} instead of @samp{@@rmacro}, an error message is given. @findex unmacro @cindex Macros, undefining @cindex Undefining macros You can undefine a macro @var{foo} with @code{@@unmacro @var{foo}}. It is not an error to undefine a macro that is already undefined. For example: @example @@unmacro foo @end example @node Invoking Macros @section Invoking Macros @cindex Invoking macros @cindex Expanding macros @cindex Running macros @cindex Macro invocation After a macro is defined (see the previous section), you can use (@dfn{invoke}) it in your document like this: @example @@@var{macroname} @{@var{arg1}, @var{arg2}, @dots{}@} @end example @noindent and the result will be just as if you typed the body of @var{macroname} at that spot. For example: @example @@macro foo @{p, q@} Together: \p\ & \q\. @@end macro @@foo@{a, b@} @end example @noindent produces: @display Together: a & b. @end display @cindex Backslash, and macros Thus, the arguments and parameters are separated by commas and delimited by braces; any whitespace after (but not before) a comma is ignored. The braces are required in the invocation (but not the definition), even when the macro takes no arguments, consistent with all other Texinfo commands. For example: @example @@macro argless @{@} No arguments here. @@end macro @@argless@{@} @end example @noindent produces: @display No arguments here. @end display @cindex Comma, in macro arguments @cindex Braces, in macro arguments To insert a comma, brace, or backslash in an argument, prepend a backslash, as in @example @@@var{macname} @{\\\@{\@}\,@} @end example @noindent which will pass the (almost certainly error-producing) argument @samp{\@{@},} to @var{macname}. However, commas in parameters, even if escaped by a backslash, might cause trouble in @TeX{}. If the macro is defined to take a single argument, and is invoked without any braces, the entire rest of the line after the macro name is supplied as the argument. For example: @example @@macro bar @{p@} Twice: \p\ & \p\. @@end macro @@bar aah @end example @noindent produces: @c Sorry for cheating, but let's not require macros to process the manual. @display Twice: aah & aah. @end display If the macro is defined to take a single argument, and is invoked with braces, the braced text is passed as the argument, regardless of commas. For example: @example @@macro bar @{p@} Twice: \p\ & \p\. @@end macro @@bar@{a,b@} @end example @noindent produces: @display Twice: a,b & a,b. @end display @node Macro Details @section Macro Details and Caveats @cindex Macro details @cindex Details of macro usage @cindex Caveats for macro usage Due to unavoidable limitations, certain macro-related constructs cause problems with @TeX{}. If you get macro-related errors when producing the printed version of a manual, try expanding the macros with @command{makeinfo} by invoking @command{texi2dvi} with the @samp{-E} option (@pxref{Format with texi2dvi}). @itemize @bullet @item As mentioned earlier, macro names must consist entirely of letters. @item It is not advisable to redefine any @TeX{} primitive, plain, or Texinfo command name as a macro. Unfortunately this is a very large set of names, and the possible resulting errors are unpredictable. @item All macros are expanded inside at least one @TeX{} group. This means that @code{@@set} and other such commands have no effect inside a macro. @item Commas in macro arguments, even if escaped by a backslash, don't always work. @item Macro arguments cannot cross lines. @item It is (usually) best to avoid comments inside macro definitions, but see the next item. @item Macros containing a command which must be on a line by itself, such as a conditional, cannot be invoked in the middle of a line. In general, the interaction of newlines in the macro definitions and invocations depends on the precise commands and context. You may be able to work around some problems with judicious use of @code{@@c}. Suppose you define a macro that is always intended to be used on a line by itself: @example @@macro linemac @@cindex whatever @@c @@end macro ... foo @@linemac bar @end example Without the @code{@@c}, there will be an unwanted blank line between the @samp{@@cindex whatever} and the @samp{bar} (one newline comes from the macro definition, one from after the invocation), causing a paragraph break. On the other hand, you wouldn't want the @code{@@c} if the macro was sometimes invoked in the middle of a line (the text after the invocation would be treated as a comment). @item In general, you can't arbitrarily substitute a macro call for Texinfo command arguments, even when the text is the same. It might work with some commands, it fails with others. Best not to do it at all. For instance, this fails: @example @@macro offmacro off @@end macro @@headings @@offmacro @end example @noindent You would expect this to be equivalent to @code{@@headings off}, but for @TeX{}nical reasons, it fails with a mysterious error message (@code{Paragraph ended before @@headings was complete}). @item Macros cannot define macros in the natural way. To do this, you must use conditionals and raw @TeX{}. For example: @example @@ifnottex @@macro ctor @{name, arg@} @@macro \name\ something involving \arg\ somehow @@end macro @@end macro @@end ifnottex @@tex \gdef\ctor#1@{\ctorx#1,@} \gdef\ctorx#1,#2,@{\def#1@{something involving #2 somehow@}@} @@end tex @end example @end itemize The @command{makeinfo} implementation also has limitations: @itemize @item @code{@@verbatim} and macros do not mix; for instance, you can't start a verbatim block inside a macro and end it outside. (@xref{verbatim}.) Starting any environment inside a macro and ending it outside may or may not work, for that matter. @item Macros that completely define macros are ok, but it's not possible to have incorrectly nested macro definitions. That is, @code{@@macro} and @code{@@end macro} (likewise for @code{@@rmacro}) must be correctly paired. For example, you cannot start a macro definition within a macro, and then end the nested definition outside the macro. @item @code{@@rmacro} is a kludge. @end itemize One more limitation is common to both implementations: white space is ignored at the beginnings of lines. Future major revisions of Texinfo may ease some of these limitations (by introducing a new macro syntax). @node alias @section @samp{@@alias @var{new}=@var{existing}} @cindex Aliases, command @cindex Command aliases @findex alias The @samp{@@alias} command defines a new command to be just like an existing one. This is useful for defining additional markup names, thus preserving semantic information in the input even though the output result may be the same. Write the @samp{@@alias} command on a line by itself, followed by the new command name, an equals sign, and the existing command name. Whitespace around the equals sign is ignored. Thus: @example @@alias @var{new} = @var{existing} @end example For example, if your document contains citations for both books and some other media (movies, for example), you might like to define a macro @code{@@moviecite@{@}} that does the same thing as an ordinary @code{@@cite@{@}} but conveys the extra semantic information as well. You'd do this as follows: @example @@alias moviecite = cite @end example Macros do not always have the same effect as aliases, due to vagaries of argument parsing. Also, aliases are much simpler to define than macros. So the command is not redundant. (It was also heavily used in the Jargon File!) Aliases must not be recursive, directly or indirectly. It is not advisable to redefine any @TeX{} primitive, plain, or Texinfo command name as an alias. Unfortunately this is a very large set of names, and the possible resulting errors are completely random. @node definfoenclose @section @samp{definfoenclose}: Customized Highlighting @cindex Highlighting, customized @cindex Customized highlighting @findex definfoenclose A @code{@@definfoenclose} command may be used to define a highlighting command for Info, but not for @TeX{}. A command defined using @code{@@definfoenclose} marks text by enclosing it in strings that precede and follow the text. You can use this to get closer control of your Info output. Presumably, if you define a command with @code{@@definfoenclose} for Info, you will create a corresponding command for @TeX{}, either in @file{texinfo.tex}, @file{texinfo.cnf}, or within an @samp{@@iftex} in your document. Write a @code{@@definfoenclose} command on a line and follow it with three arguments separated by commas. The first argument to @code{@@definfoenclose} is the @@-command name (without the @code{@@}); the second argument is the Info start delimiter string; and the third argument is the Info end delimiter string. The latter two arguments enclose the highlighted text in the Info file. A delimiter string may contain spaces. Neither the start nor end delimiter is required. If you do not want a start delimiter but do want an end delimiter, you must follow the command name with two commas in a row; otherwise, the Info formatting commands will naturally misinterpret the end delimiter string you intended as the start delimiter string. If you do a @code{@@definfoenclose} on the name of a pre-defined macro (such as @code{@@emph}, @code{@@strong}, @code{@@t}, or @code{@@i}), the enclosure definition will override the built-in definition. An enclosure command defined this way takes one argument in braces; this is intended for new markup commands (@pxref{Marking Text}). @findex phoo For example, you can write: @example @@definfoenclose phoo,//,\\ @end example @noindent near the beginning of a Texinfo file to define @code{@@phoo} as an Info formatting command that inserts `//' before and `\\' after the argument to @code{@@phoo}. You can then write @code{@@phoo@{bar@}} wherever you want `//bar\\' highlighted in Info. Also, for @TeX{} formatting, you could write @example @@iftex @@global@@let@@phoo=@@i @@end iftex @end example @noindent to define @code{@@phoo} as a command that causes @TeX{} to typeset the argument to @code{@@phoo} in italics. Each definition applies to its own formatter: one for @TeX{}, the other for @code{texinfo-format-buffer} or @code{texinfo-format-region}. The @code{@@definfoenclose} command need not be within @samp{@@ifinfo}, but the raw @TeX{} commands do need to be in @samp{@@iftex}. @findex headword Here is another example: write @example @@definfoenclose headword, , : @end example @noindent near the beginning of the file, to define @code{@@headword} as an Info formatting command that inserts nothing before and a colon after the argument to @code{@@headword}. @samp{@@definfoenclose} definitions must not be recursive, directly or indirectly. @node Hardcopy @chapter Formatting and Printing Hardcopy @cindex Format and print hardcopy @cindex Printing hardcopy @cindex Hardcopy, printing it @cindex Making a printed manual @cindex Sorting indices @cindex Indices, sorting @cindex @TeX{} index sorting @pindex texindex There are three major shell commands for making a printed manual from a Texinfo file: one for converting the Texinfo file into a file that will be printed, a second for sorting indices, and a third for printing the formatted document. When you use the shell commands, you can either work directly in the operating system shell or work within a shell inside GNU Emacs. If you are using GNU Emacs, you can use commands provided by Texinfo mode instead of shell commands. In addition to the three commands to format a file, sort the indices, and print the result, Texinfo mode offers key bindings for commands to recenter the output buffer, show the print queue, and delete a job from the print queue. @menu * Use TeX:: Use @TeX{} to format for hardcopy. * Format with tex/texindex:: How to format with explicit shell commands. * Format with texi2dvi:: A simpler way to format. * Print with lpr:: How to print. * Within Emacs:: How to format and print from an Emacs shell. * Texinfo Mode Printing:: How to format and print in Texinfo mode. * Compile-Command:: How to print using Emacs's compile command. * Requirements Summary:: @TeX{} formatting requirements summary. * Preparing for TeX:: What to do before you use @TeX{}. * Overfull hboxes:: What are and what to do with overfull hboxes. * smallbook:: How to print small format books and manuals. * A4 Paper:: How to print on A4 or A5 paper. * pagesizes:: How to print with customized page sizes. * Cropmarks and Magnification:: How to print marks to indicate the size of pages and how to print scaled up output. * PDF Output:: Portable Document Format output. * Obtaining TeX:: How to Obtain @TeX{}. @end menu @node Use TeX @section Use @TeX{} The typesetting program called @TeX{} is used for formatting a Texinfo file. @TeX{} is a very powerful typesetting program and, if used correctly, does an exceptionally good job. (@xref{Obtaining TeX, , How to Obtain @TeX{}}, for information on how to obtain @TeX{}.) The standalone @code{makeinfo} program and Emacs functions @code{texinfo-format-region} and @code{texinfo-format-buffer} commands read the very same @@-commands in the Texinfo file as does @TeX{}, but process them differently to make an Info file (@pxref{Creating an Info File}). @node Format with tex/texindex @section Format with @code{tex} and @code{texindex} @cindex Shell formatting with @code{tex} and @code{texindex} @cindex Formatting with @code{tex} and @code{texindex} @cindex DVI file You can format the Texinfo file with the shell command @code{tex} followed by the name of the Texinfo file. For example: @example tex foo.texi @end example @noindent @TeX{} will produce a @dfn{DVI file} as well as several auxiliary files containing information for indices, cross references, etc. The DVI file (for @dfn{DeVice Independent} file) can be printed on virtually any device (see the following sections). @pindex texindex The @code{tex} formatting command itself does not sort the indices; it writes an output file of unsorted index data. To generate a printed index after running the @command{tex} command, you first need a sorted index to work from. The @command{texindex} command sorts indices. (The source file @file{texindex.c} comes as part of the standard Texinfo distribution, among other places.) (@command{texi2dvi} runs @command{tex} and @command{texindex} as necessary.) @cindex Names of index files @cindex Index file names The @code{tex} formatting command outputs unsorted index files under names that obey a standard convention: the name of your main input file with any @samp{.tex} (or similar, @pxref{tex invocation,,, web2c, Web2c}) extension removed, followed by the two letter names of indices. For example, the raw index output files for the input file @file{foo.texinfo} would be @file{foo.cp}, @file{foo.vr}, @file{foo.fn}, @file{foo.tp}, @file{foo.pg} and @file{foo.ky}. Those are exactly the arguments to give to @code{texindex}. @need 1000 @cindex Wildcards @cindex Globbing Instead of specifying all the unsorted index file names explicitly, you can use @samp{??} as shell wildcards and give the command in this form: @example texindex foo.?? @end example @noindent This command will run @code{texindex} on all the unsorted index files, including any that you have defined yourself using @code{@@defindex} or @code{@@defcodeindex}. (You may execute @samp{texindex foo.??} even if there are similarly named files with two letter extensions that are not index files, such as @samp{foo.el}. The @code{texindex} command reports but otherwise ignores such files.) For each file specified, @code{texindex} generates a sorted index file whose name is made by appending @samp{s} to the input file name. The @code{@@printindex} command looks for a file with that name (@pxref{Printing Indices & Menus}). @code{texindex} does not alter the raw index output file. After you have sorted the indices, you need to rerun @code{tex} on the Texinfo file. This regenerates the DVI file, this time with up-to-date index entries. Finally, you may need to run @code{tex} one more time, to get the page numbers in the cross-references correct. To summarize, this is a five step process: @enumerate @item Run @code{tex} on your Texinfo file. This generates a DVI file (with undefined cross-references and no indices), and the raw index files (with two letter extensions). @item Run @code{texindex} on the raw index files. This creates the corresponding sorted index files (with three letter extensions). @item Run @code{tex} again on your Texinfo file. This regenerates the DVI file, this time with indices and defined cross-references, but with page numbers for the cross-references from last time, generally incorrect. @item Sort the indices again, with @code{texindex}. @item Run @code{tex} one last time. This time the correct page numbers are written for the cross-references. @end enumerate @pindex texi2dvi Alternatively, it's a one-step process: run @code{texi2dvi} (@pxref{Format with texi2dvi}). You need not run @code{texindex} each time after you run @code{tex}. If you do not, on the next run, the @code{tex} formatting command will use whatever sorted index files happen to exist from the previous use of @code{texindex}. This is usually ok while you are debugging. @cindex Auxiliary files, avoiding @findex novalidate @cindex Pointer validation, suppressing @cindex Chapters, formatting one at a time Sometimes you may wish to print a document while you know it is incomplete, or to print just one chapter of a document. In that case, the usual auxiliary files that @TeX{} creates and warnings @TeX{} gives when cross-references are not satisfied are just nuisances. You can avoid them with the @code{@@novalidate} command, which you must give @emph{before} the @code{@@setfilename} command (@pxref{setfilename,,@code{@@setfilename}}). Thus, the beginning of your file would look approximately like this: @example \input texinfo @@novalidate @@setfilename myfile.info @dots{} @end example @noindent @code{@@novalidate} also turns off validation in @code{makeinfo}, just like its @code{--no-validate} option (@pxref{Pointer Validation}). @node Format with texi2dvi @section Format with @code{texi2dvi} @pindex texi2dvi @r{(shell script)} The @code{texi2dvi} command automatically runs both @TeX{} and @command{texindex} as many times as necessary to produce a DVI file with sorted indices and all cross-references resolved. It is therefore simpler than manually executing the @code{tex}---@code{texindex}---@code{tex}---@code{tex} sequence described in the previous section. To run @code{texi2dvi} on an input file @file{foo.texi}, do this (where @samp{prompt$ } is your shell prompt): @example prompt$ @kbd{texi2dvi foo.texi} @end example As shown in this example, the input filenames to @code{texi2dvi} must include any extension (@samp{.texi}, @samp{.texinfo}, etc.). Under MS-DOS and perhaps in other circumstances, you may need to run @samp{sh texi2dvi foo.texi} instead of relying on the operating system to invoke the shell on the @samp{texi2dvi} script. Perhaps the most useful option to @code{texi2dvi} is @samp{--command=@var{cmd}}. This inserts @var{cmd} on a line by itself after the @code{@@setfilename} in a temporary copy of the input file before running @TeX{}. With this, you can specify different printing formats, such as @code{@@smallbook} (@pxref{smallbook}), @code{@@afourpaper} (@pxref{A4 Paper}), or @code{@@pagesizes} (@pxref{pagesizes}), without actually changing the document source. (You can also do this on a site-wide basis with @file{texinfo.cnf}; @pxref{Preparing for TeX,,Preparing for @TeX{}}). With the @option{--pdf} option, @command{texi2dvi} produces PDF output instead of DVI (@pxref{PDF Output}), by running @command{pdftex} instead of @command{tex}. Alternatively, the command @command{texi2pdf} is an abbreviation for running @samp{texi2dvi --pdf}. @cindex @LaTeX{}, processing with @command{texi2dvi} @command{texi2dvi} can also be used to process @LaTeX{} files; simply run @samp{texi2dvi filename.ext}. @command{texi2dvi} will use @command{etex} (or @command{pdfetex}) if they are available; these extended versions of @TeX{} are not required, and the DVI (or PDF) output is identical, but they simplify the @TeX{} programming in some cases, and provide additional tracing information when debugging @file{texinfo.tex}. For a list of other options, run @samp{texi2dvi --help}. @node Print with lpr @section Shell Print Using @code{lpr -d} @pindex lpr @r{(DVI print command)} The precise command to print a DVI file depends on your system installation. Two common ones are @samp{dvips foo.dvi -o} and @samp{lpr -d foo.dvi}. For example, the following commands will (perhaps) suffice to sort the indices, format, and print the @cite{Bison Manual}: @example @group tex bison.texinfo texindex bison.?? tex bison.texinfo lpr -d bison.dvi @end group @end example @noindent (Remember that the shell commands may be different at your site; but these are commonly used versions.) Using the @code{texi2dvi} shell script (see the previous section): @example @group texi2dvi bison.texinfo lpr -d bison.dvi # or perhaps dvips bison.dvi -o @end group @end example @cindex Shell printing, on MS-DOS/MS-Windows @cindex Printing DVI files, on MS-DOS/MS-Windows @pindex lpr@r{-d, replacements on MS-DOS/MS-Windows} @code{lpr} is a standard program on Unix systems, but it is usually absent on MS-DOS/MS-Windows. Some network packages come with a program named @code{lpr}, but these are usually limited to sending files to a print server over the network, and generally don't support the @samp{-d} option. If you are unfortunate enough to work on one of these systems, you have several alternative ways of printing DVI files: @itemize @bullet{} @item Find and install a Unix-like @code{lpr} program, or its clone. If you can do that, you will be able to print DVI files just like described above. @item Send the DVI files to a network printer queue for DVI files. Some network printers have special queues for printing DVI files. You should be able to set up your network software to send files to that queue. In some cases, the version of @code{lpr} which comes with your network software will have a special option to send a file to specific queues, like this: @example lpr -Qdvi -hprint.server.domain bison.dvi @end example @item Convert the DVI file to a Postscript or PCL file and send it to your local printer. @xref{Invoking Dvips,,, dvips, Dvips}, and the man pages for @code{dvilj}, for detailed description of these tools. Once the DVI file is converted to the format your local printer understands directly, just send it to the appropriate port, usually @samp{PRN}. @end itemize @node Within Emacs @section From an Emacs Shell @cindex Print, format from Emacs shell @cindex Format, print from Emacs shell @cindex Shell, format, print from @cindex Emacs shell, format, print from @cindex GNU Emacs shell, format, print from You can give formatting and printing commands from a shell within GNU Emacs. To create a shell within Emacs, type @kbd{M-x shell}. In this shell, you can format and print the document. @xref{Hardcopy, , Format and Print Hardcopy}, for details. You can switch to and from the shell buffer while @code{tex} is running and do other editing. If you are formatting a long document on a slow machine, this can be very convenient.@refill You can also use @code{texi2dvi} from an Emacs shell. For example, here is how to use @code{texi2dvi} to format and print @cite{Using and Porting GNU CC} from a shell within Emacs: @example @group texi2dvi gcc.texinfo lpr -d gcc.dvi @end group @end example See the next section for more information about formatting and printing in Texinfo mode. @node Texinfo Mode Printing @section Formatting and Printing in Texinfo Mode @cindex Region printing in Texinfo mode @cindex Format and print in Texinfo mode @cindex Print and format in Texinfo mode Texinfo mode provides several predefined key commands for @TeX{} formatting and printing. These include commands for sorting indices, looking at the printer queue, killing the formatting job, and recentering the display of the buffer in which the operations occur.@refill @table @kbd @item C-c C-t C-b @itemx M-x texinfo-tex-buffer Run @code{texi2dvi} on the current buffer.@refill @item C-c C-t C-r @itemx M-x texinfo-tex-region Run @TeX{} on the current region.@refill @item C-c C-t C-i @itemx M-x texinfo-texindex Sort the indices of a Texinfo file formatted with @code{texinfo-tex-region}.@refill @item C-c C-t C-p @itemx M-x texinfo-tex-print Print a DVI file that was made with @code{texinfo-tex-region} or @code{texinfo-tex-buffer}.@refill @item C-c C-t C-q @itemx M-x tex-show-print-queue Show the print queue.@refill @item C-c C-t C-d @itemx M-x texinfo-delete-from-print-queue Delete a job from the print queue; you will be prompted for the job number shown by a preceding @kbd{C-c C-t C-q} command (@code{texinfo-show-tex-print-queue}).@refill @item C-c C-t C-k @itemx M-x tex-kill-job Kill the currently running @TeX{} job started by either @code{texinfo-tex-region} or @code{texinfo-tex-buffer}, or any other process running in the Texinfo shell buffer.@refill @item C-c C-t C-x @itemx M-x texinfo-quit-job Quit a @TeX{} formatting job that has stopped because of an error by sending an @key{x} to it. When you do this, @TeX{} preserves a record of what it did in a @file{.log} file.@refill @item C-c C-t C-l @itemx M-x tex-recenter-output-buffer Redisplay the shell buffer in which the @TeX{} printing and formatting commands are run to show its most recent output.@refill @end table @need 1000 Thus, the usual sequence of commands for formatting a buffer is as follows (with comments to the right):@refill @example @group C-c C-t C-b @r{Run @code{texi2dvi} on the buffer.} C-c C-t C-p @r{Print the DVI file.} C-c C-t C-q @r{Display the printer queue.} @end group @end example The Texinfo mode @TeX{} formatting commands start a subshell in Emacs called the @file{*tex-shell*}. The @code{texinfo-tex-command}, @code{texinfo-texindex-command}, and @code{tex-dvi-print-command} commands are all run in this shell. You can watch the commands operate in the @samp{*tex-shell*} buffer, and you can switch to and from and use the @samp{*tex-shell*} buffer as you would any other shell buffer.@refill @need 1500 The formatting and print commands depend on the values of several variables. The default values are:@refill @example @group @r{Variable} @r{Default value} texinfo-texi2dvi-command "texi2dvi" texinfo-tex-command "tex" texinfo-texindex-command "texindex" texinfo-delete-from-print-queue-command "lprm" texinfo-tex-trailer "@@bye" tex-start-of-header "%**start" tex-end-of-header "%**end" tex-dvi-print-command "lpr -d" tex-show-queue-command "lpq" @end group @end example You can change the values of these variables with the @kbd{M-x set-variable} command (@pxref{Examining, , Examining and Setting Variables, emacs, The GNU Emacs Manual}), or with your @file{.emacs} initialization file (@pxref{Init File, , , emacs, The GNU Emacs Manual}). @cindex Customize Emacs package (@t{Development/Docs/Texinfo}) Beginning with version 20, GNU Emacs offers a user-friendly interface, called @dfn{Customize}, for changing values of user-definable variables. @xref{Easy Customization, , Easy Customization Interface, emacs, The GNU Emacs Manual}, for more details about this. The Texinfo variables can be found in the @samp{Development/Docs/Texinfo} group, once you invoke the @kbd{M-x customize} command. @node Compile-Command @section Using the Local Variables List @cindex Local variables @cindex Compile command for formatting @cindex Format with the compile command Yet another way to apply the @TeX{} formatting command to a Texinfo file is to put that command in a @dfn{local variables list} at the end of the Texinfo file. You can then specify the @code{tex} or @code{texi2dvi} commands as a @code{compile-command} and have Emacs run it by typing @kbd{M-x compile}. This creates a special shell called the @file{*compilation*} buffer in which Emacs runs the compile command. For example, at the end of the @file{gdb.texinfo} file, after the @code{@@bye}, you could put the following:@refill @example @group Local Variables: compile-command: "texi2dvi gdb.texinfo" End: @end group @end example @noindent This technique is most often used by programmers who also compile programs this way; see @ref{Compilation, , , emacs, The GNU Emacs Manual}.@refill @node Requirements Summary @section @TeX{} Formatting Requirements Summary @cindex Requirements for formatting @cindex Minimal requirements for formatting @cindex Formatting requirements Every Texinfo file that is to be input to @TeX{} must begin with a @code{\input} command and must contain an @code{@@setfilename} command: @example \input texinfo @@setfilename @var{arg-not-used-by-@TeX{}} @end example @noindent The first command instructs @TeX{} to load the macros it needs to process a Texinfo file and the second command opens auxiliary files. Every Texinfo file must end with a line that terminates @TeX{}'s processing and forces out unfinished pages: @example @@bye @end example Strictly speaking, these lines are all a Texinfo file needs to be processed successfully by @TeX{}. Usually, however, the beginning includes an @code{@@settitle} command to define the title of the printed manual, an @code{@@setchapternewpage} command, a title page, a copyright page, and permissions. Besides an @code{@@bye}, the end of a file usually includes indices and a table of contents. (And of course most manuals contain a body of text as well.) For more information, see: @itemize @bullet @item @ref{settitle, , @code{@@settitle}}. @item @ref{setchapternewpage, , @code{@@setchapternewpage}}. @item @ref{Headings, ,Page Headings}. @item @ref{Titlepage & Copyright Page}. @item @ref{Printing Indices & Menus}. @item @ref{Contents}. @end itemize @node Preparing for TeX @section Preparing for @TeX{} @cindex Preparing for @TeX{} @cindex @TeX{} input initialization @cindex @b{.profile} initialization file @cindex @b{.cshrc} initialization file @cindex Initialization file for @TeX{} input @TeX{} needs to know where to find the @file{texinfo.tex} file that the @samp{\input texinfo} command on the first line reads. The @file{texinfo.tex} file tells @TeX{} how to handle @@-commands; it is included in all standard GNU distributions. The latest version is always available from the Texinfo source repository: @smalldisplay @uref{http://savannah.gnu.org/cgi-bin/viewcvs/texinfo/texinfo/doc/texinfo.tex?rev=HEAD} @end smalldisplay @pindex texinfo.tex@r{, installing} Usually, the installer has put the @file{texinfo.tex} file in the default directory that contains @TeX{} macros when GNU Texinfo, Emacs or other GNU software is installed. In this case, @TeX{} will find the file and you do not need to do anything special. If this has not been done, you can put @file{texinfo.tex} in the current directory when you run @TeX{}, and @TeX{} will find it there. @pindex epsf.tex@r{, installing} Also, you should install @file{epsf.tex}, if it is not already installed from another distribution. More details are at the end of the description of the @code{@@image} command (@pxref{Images}). @pindex pdfcolor.tex@r{, installing} Likewise for @file{pdfcolor.tex}, if it is not already installed and you use pdftex. @pindex texinfo.cnf @r{installation} @cindex Customizing of @TeX{} for Texinfo @cindex Site-wide Texinfo configuration file Optionally, you may create an additional @file{texinfo.cnf}, and install it as well. This file is read by @TeX{} when the @code{@@setfilename} command is executed (@pxref{setfilename,, @code{@@setfilename}}). You can put any commands you like there, according to local site-wide conventions. They will be read by @TeX{} when processing any Texinfo document. For example, if @file{texinfo.cnf} contains the line @samp{@@afourpaper} (@pxref{A4 Paper}), then all Texinfo documents will be processed with that page size in effect. If you have nothing to put in @file{texinfo.cnf}, you do not need to create it. @cindex Environment variable @code{TEXINPUTS} @vindex TEXINPUTS If neither of the above locations for these system files suffice for you, you can specify the directories explicitly. For @file{texinfo.tex}, you can do this by writing the complete path for the file after the @code{\input} command. Another way, that works for both @file{texinfo.tex} and @file{texinfo.cnf} (and any other file @TeX{} might read), is to set the @code{TEXINPUTS} environment variable in your @file{.cshrc} or @file{.profile} file. Which you use of @file{.cshrc} or @file{.profile} depends on whether you use a Bourne shell-compatible (@code{sh}, @code{bash}, @code{ksh}, @dots{}) or C shell-compatible (@code{csh}, @code{tcsh}) command interpreter. The latter read the @file{.cshrc} file for initialization information, and the former read @file{.profile}. In a @file{.cshrc} file, you could use the following @code{csh} command sequence: @example setenv TEXINPUTS .:/home/me/mylib: @end example @need 1000 In a @file{.profile} file, you could use the following @code{sh} command sequence: @example @group TEXINPUTS=.:/home/me/mylib: export TEXINPUTS @end group @end example On MS-DOS/MS-Windows, you would say it like this@footnote{Note the use of the @samp{;} character, instead of @samp{:}, as directory separator on these systems.}: @example @group set TEXINPUTS=.;d:/home/me/mylib;c: @end group @end example @noindent It is customary for DOS/Windows users to put such commands in the @file{autoexec.bat} file, or in the Windows Registry. @noindent These settings would cause @TeX{} to look for @file{\input} file first in the current directory, indicated by the @samp{.}, then in a hypothetical user @samp{me}'s @file{mylib} directory, and finally in the system directories. (A leading, trailing, or doubled @samp{:} indicates searching the system directories at that point.) @cindex Dumping a .fmt file @cindex Format file, dumping Finally, you may wish to dump a @file{.fmt} file (@pxref{Memory dumps,,, web2c, Web2c}) so that @TeX{} can load Texinfo faster. (The disadvantage is that then updating @file{texinfo.tex} requires redumping.) You can do this by running this command, assuming @file{epsf.tex} is findable by @TeX{}: @example initex texinfo @@dump @end example (@code{dump} is a @TeX{} primitive.) Then, move @file{texinfo.fmt} to wherever your @code{.fmt} files are found; typically, this will be in the subdirectory @file{web2c} of your @TeX{} installation. @node Overfull hboxes @section Overfull ``hboxes'' @cindex Overfull @samp{hboxes} @cindex @samp{hboxes}, overfull @cindex Final output @TeX{} is sometimes unable to typeset a line without extending it into the right margin. This can occur when @TeX{} comes upon what it interprets as a long word that it cannot hyphenate, such as an electronic mail network address or a very long title. When this happens, @TeX{} prints an error message like this: @example Overfull @@hbox (20.76302pt too wide) @end example @findex hbox @noindent (In @TeX{}, lines are in ``horizontal boxes'', hence the term, ``hbox''. @samp{@@hbox} is a @TeX{} primitive not needed in the Texinfo language.) @TeX{} also provides the line number in the Texinfo source file and the text of the offending line, which is marked at all the places that @TeX{} considered hyphenation. @xref{Debugging with TeX, , Catching Errors with @TeX{} Formatting}, for more information about typesetting errors. If the Texinfo file has an overfull hbox, you can rewrite the sentence so the overfull hbox does not occur, or you can decide to leave it. A small excursion into the right margin often does not matter and may not even be noticeable. If you have many overfull boxes and/or an antipathy to rewriting, you can coerce @TeX{} into greatly increasing the allowable interword spacing, thus (if you're lucky) avoiding many of the bad line breaks, like this: @findex \emergencystretch @example @@tex \global\emergencystretch = .9\hsize @@end tex @end example @noindent (You should adjust the fraction as needed.) This huge value for @code{\emergencystretch} cannot be the default, since then the typeset output would generally be of noticeably lower quality; the default is @samp{.15\hsize}. @code{\hsize} is the @TeX{} dimension containing the current line width. @cindex Black rectangle in hardcopy @cindex Rectangle, black in hardcopy @cindex Box, ugly black in hardcopy @cindex Ugly black rectangles in hardcopy For what overfull boxes you have, however, @TeX{} will print a large, ugly, black rectangle beside the line that contains the overfull hbox unless told otherwise. This is so you will notice the location of the problem if you are correcting a draft. @findex finalout To prevent such a monstrosity from marring your final printout, write the following in the beginning of the Texinfo file on a line of its own, before the @code{@@titlepage} command: @example @@finalout @end example @node smallbook @section Printing ``Small'' Books @findex smallbook @cindex Small book size @cindex Book, printing small @cindex Page sizes for books @cindex Size of printed book By default, @TeX{} typesets pages for printing in an 8.5 by 11 inch format. However, you can direct @TeX{} to typeset a document in a 7 by 9.25 inch format that is suitable for bound books by inserting the following command on a line by itself at the beginning of the Texinfo file, before the title page:@refill @example @@smallbook @end example @noindent (Since many books are about 7 by 9.25 inches, this command might better have been called the @code{@@regularbooksize} command, but it came to be called the @code{@@smallbook} command by comparison to the 8.5 by 11 inch format.) If you write the @code{@@smallbook} command between the start-of-header and end-of-header lines, the Texinfo mode @TeX{} region formatting command, @code{texinfo-tex-region}, will format the region in ``small'' book size (@pxref{Start of Header}).@refill @xref{small}, for information about commands that make it easier to produce examples for a smaller manual. @xref{Format with texi2dvi}, and @ref{Preparing for TeX,,Preparing for @TeX{}}, for other ways to format with @code{@@smallbook} that do not require changing the source file. @node A4 Paper @section Printing on A4 Paper @cindex A4 paper, printing on @cindex A5 paper, printing on @cindex Paper size, A4 @cindex European A4 paper @findex afourpaper You can tell @TeX{} to format a document for printing on European size A4 paper (or A5) with the @code{@@afourpaper} (or @code{@@afivepaper}) command. Write the command on a line by itself near the beginning of the Texinfo file, before the title page. For example, this is how you would write the header for this manual: @example @group \input texinfo @@c -*-texinfo-*- @@c %**start of header @@setfilename texinfo @@settitle Texinfo @@afourpaper @@c %**end of header @end group @end example @xref{Format with texi2dvi}, and @ref{Preparing for TeX,,Preparing for @TeX{}}, for other ways to format for different paper sizes that do not require changing the source file. @findex afourlatex @findex afourwide You may or may not prefer the formatting that results from the command @code{@@afourlatex}. There's also @code{@@afourwide} for A4 paper in wide format. @node pagesizes @section @code{@@pagesizes} [@var{width}][, @var{height}]: Custom Page Sizes @findex pagesizes @cindex Custom page sizes @cindex Page sizes, customized @cindex Text width and height @cindex Width of text area @cindex Height of text area @cindex Depth of text area You can explicitly specify the height and (optionally) width of the main text area on the page with the @code{@@pagesizes} command. Write this on a line by itself near the beginning of the Texinfo file, before the title page. The height comes first, then the width if desired, separated by a comma. Examples: @example @@pagesizes 200mm,150mm @c for b5 paper @end example @noindent and @example @@pagesizes 11.5in @c for legal paper @end example @cindex B5 paper, printing on @cindex Legal paper, printing on This would be reasonable for printing on B5-size paper. To emphasize, this command specifies the size of the @emph{text area}, not the size of the paper (which is 250@dmn{mm} by 177@dmn{mm} for B5, 14@dmn{in} by 8.5@dmn{in} for legal). @cindex Margins on page, not controllable To make more elaborate changes, such as changing any of the page margins, you must define a new command in @file{texinfo.tex} (or @file{texinfo.cnf}, @pxref{Preparing for TeX,,Preparing for @TeX{}}). @xref{Format with texi2dvi}, and @ref{Preparing for TeX,,Preparing for @TeX{}}, for other ways to specify @code{@@pagesizes} that do not require changing the source file. @code{@@pagesizes} is ignored by @code{makeinfo}. @node Cropmarks and Magnification @section Cropmarks and Magnification @findex cropmarks @cindex Cropmarks for printing @cindex Printing cropmarks You can (attempt to) direct @TeX{} to print cropmarks at the corners of pages with the @code{@@cropmarks} command. Write the @code{@@cropmarks} command on a line by itself between @code{@@iftex} and @code{@@end iftex} lines near the beginning of the Texinfo file, before the title page, like this:@refill @example @group @@iftex @@cropmarks @@end iftex @end group @end example This command is mainly for printers that typeset several pages on one sheet of film; but you can attempt to use it to mark the corners of a book set to 7 by 9.25 inches with the @code{@@smallbook} command. (Printers will not produce cropmarks for regular sized output that is printed on regular sized paper.) Since different printing machines work in different ways, you should explore the use of this command with a spirit of adventure. You may have to redefine the command in @file{texinfo.tex}. @findex \mag @r{(raw @TeX{} magnification)} @cindex Magnified printing @cindex Larger or smaller pages You can attempt to direct @TeX{} to typeset pages larger or smaller than usual with the @code{\mag} @TeX{} command. Everything that is typeset is scaled proportionally larger or smaller. (@code{\mag} stands for ``magnification''.) This is @emph{not} a Texinfo @@-command, but is a plain @TeX{} command that is prefixed with a backslash. You have to write this command between @code{@@tex} and @code{@@end tex} (@pxref{Raw Formatter Commands}). Follow the @code{\mag} command with an @samp{=} and then a number that is 1000 times the magnification you desire. For example, to print pages at 1.2 normal size, write the following near the beginning of the Texinfo file, before the title page: @example @group @@tex \mag=1200 @@end tex @end group @end example With some printing technologies, you can print normal-sized copies that look better than usual by giving a larger-than-normal master to your print shop. They do the reduction, thus effectively increasing the resolution. Depending on your system, DVI files prepared with a nonstandard-@code{\mag} may not print or may print only with certain magnifications. Be prepared to experiment. @node PDF Output @section PDF Output @cindex PDF output @pindex pdftex The simplest way to generate PDF output from Texinfo source is to run the convenience script @command{texi2pdf}; this simply executes the @command{texi2dvi} script with the @option{--pdf} option (@pxref{Format with texi2dvi}). If for some reason you want to process by hand, simply run the @command{pdftex} program instead of plain @command{tex}. That is, run @samp{pdftex foo.texi} instead of @samp{tex foo.texi}. @dfn{PDF} stands for `Portable Document Format'. It was invented by Adobe Systems some years ago for document interchange, based on their PostScript language. Related links: @itemize @item GNU GV, a @uref{http://www.foolabs.com/xpdf/, Ghostscript-based PDF reader}. (It can also preview PostScript documents.) @item A freely available standalone @uref{http://www.foolabs.com/xpdf/, PDF reader} for the X window system. @item @uref{http://partners.adobe.com/asn/acrobat/sdk/public/docs/, PDF definition}. @end itemize At present, Texinfo does not provide @samp{@@ifpdf} or @samp{@@pdf} commands as for the other output formats, since PDF documents contain many internal links that would be hard or impossible to get right at the Texinfo source level. PDF files require special software to be displayed, unlike the plain ASCII formats (Info, HTML) that Texinfo supports. They also tend to be much larger than the DVI files output by @TeX{} by default. Nevertheless, a PDF file does define an actual typeset document in a self-contained file, so it has its place. @node Obtaining TeX @section How to Obtain @TeX{} @cindex Obtaining @TeX{} @cindex @TeX{}, how to obtain @c !!! Here is information about obtaining TeX. Update it whenever. @c !!! Also consider updating TeX.README on ftp.gnu.org. @c Updated by RJC on 1 March 1995, conversation with MacKay. @c Updated by kb@cs.umb.edu on 29 July 1996. @c Updated by kb@cs.umb.edu on 25 April 1997. @c Updated by kb@cs.umb.edu on 27 February 1998. @TeX{} is freely redistributable. You can obtain @TeX{} for Unix systems via anonymous ftp or on physical media. The core material consists of the Web2c @TeX{} distribution (@uref{http://tug.org/web2c}). Instructions for retrieval by anonymous ftp and information on other available distributions: @uref{http://tug.org/unixtex.ftp}. The Free Software Foundation provides a core distribution on its Source Code CD-ROM suitable for printing Texinfo manuals. To order it, contact: @display @group Free Software Foundation, Inc. 59 Temple Place Suite 330 Boston, MA @ @ 02111-1307 USA Telephone: @w{+1-617-542-5942} Fax: (including Japan) @w{+1-617-542-2652} Free Dial Fax (in Japan): @w{ } @w{ } @w{ } 0031-13-2473 (KDD) @w{ } @w{ } @w{ } 0066-3382-0158 (IDC) Electronic mail: @code{gnu@@gnu.org} @end group @end display Many other @TeX{} distributions are available; see @uref{http://tug.org/}. @node Creating and Installing Info Files @chapter Creating and Installing Info Files This chapter describes how to create and install Info files. @xref{Info Files}, for general information about the file format itself. @menu * Creating an Info File:: * Installing an Info File:: @end menu @node Creating an Info File @section Creating an Info File @cindex Creating an Info file @cindex Info, creating an online file @cindex Formatting a file for Info @code{makeinfo} is a program that converts a Texinfo file into an Info file, HTML file, or plain text. @code{texinfo-format-region} and @code{texinfo-format-buffer} are GNU Emacs functions that convert Texinfo to Info. For information on installing the Info file in the Info system, @pxref{Installing an Info File}. @menu * makeinfo advantages:: @code{makeinfo} provides better error checking. * Invoking makeinfo:: How to run @code{makeinfo} from a shell. * makeinfo options:: Specify fill-column and other options. * Pointer Validation:: How to check that pointers point somewhere. * makeinfo in Emacs:: How to run @code{makeinfo} from Emacs. * texinfo-format commands:: Two Info formatting commands written in Emacs Lisp are an alternative to @code{makeinfo}. * Batch Formatting:: How to format for Info in Emacs Batch mode. * Tag and Split Files:: How tagged and split files help Info to run better. @end menu @node makeinfo advantages @subsection @code{makeinfo} Preferred The @code{makeinfo} utility creates an Info file from a Texinfo source file more quickly than either of the Emacs formatting commands and provides better error messages. We recommend it. @code{makeinfo} is a C program that is independent of Emacs. You do not need to run Emacs to use @code{makeinfo}, which means you can use @code{makeinfo} on machines that are too small to run Emacs. You can run @code{makeinfo} in any one of three ways: from an operating system shell, from a shell inside Emacs, or by typing the @kbd{C-c C-m C-r} or the @kbd{C-c C-m C-b} command in Texinfo mode in Emacs. The @code{texinfo-format-region} and the @code{texinfo-format-buffer} commands are useful if you cannot run @code{makeinfo}. Also, in some circumstances, they format short regions or buffers more quickly than @code{makeinfo}. @node Invoking makeinfo @subsection Running @code{makeinfo} from a Shell @pindex makeinfo To create an Info file from a Texinfo file, invoke @command{makeinfo} followed by the name of the Texinfo file. Thus, to create the Info file for Bison, type the following to the shell: @example makeinfo bison.texinfo @end example (You can run a shell inside Emacs by typing @kbd{M-x shell}.) @command{makeinfo} has many options to control its actions and output; see the next section. @node makeinfo options @subsection Options for @code{makeinfo} @cindex @code{makeinfo} options @cindex Options for @code{makeinfo} The @command{makeinfo} program accepts many options. Perhaps the most commonly needed are those that change the output format. By default, @command{makeinfo} outputs Info files. Each command line option is a word preceded by @samp{--} or a letter preceded by @samp{-}. You can use abbreviations for the long option names as long as they are unique. For example, you could use the following shell command to create an Info file for @file{bison.texinfo} in which each line is filled to only 68 columns: @example makeinfo --fill-column=68 bison.texinfo @end example You can write two or more options in sequence, like this:@refill @example makeinfo --no-split --fill-column=70 @dots{} @end example @noindent This would keep the Info file together as one possibly very long file and would also set the fill column to 70. The options are: @table @code @item -D @var{var} @opindex -D @var{var} Cause the variable @var{var} to be defined. This is equivalent to @code{@@set @var{var}} in the Texinfo file (@pxref{set clear value}). @item --commands-in-node-names @opindex --commands-in-node-names Allow @code{@@}-commands in node names. This is not recommended, as it can probably never be implemented in @TeX{}. It also makes @code{makeinfo} much slower. Also, this option is ignored when @samp{--no-validate} is used. @xref{Pointer Validation}, for more details. @item --css-include=@var{file} @opindex --css-include Include the contents of @var{file}, which should contain cascading style sheets specifications, in the @samp{<style>} block of the HTML output. @xref{HTML CSS}. If @var{file} is @samp{-}, read standard input. @item --docbook @opindex --docbook Generate Docbook output rather than Info. @item --enable-encoding @opindex --enable-encoding Output accented and special characters in Info or plain text output based on @samp{@@documentencoding}. @xref{documentencoding,,@code{documentencoding}}, and @ref{Inserting Accents}. @item --error-limit=@var{limit} @itemx -e @var{limit} @opindex --error-limit=@var{limit} @opindex -e @var{limit} Set the maximum number of errors that @code{makeinfo} will report before exiting (on the assumption that continuing would be useless); default 100. @item --fill-column=@var{width} @itemx -f @var{width} @opindex --fill-column=@var{width} @opindex -f @var{width} Specify the maximum number of columns in a line; this is the right-hand edge of a line. Paragraphs that are filled will be filled to this width. (Filling is the process of breaking up and connecting lines so that lines are the same length as or shorter than the number specified as the fill column. Lines are broken between words.) The default value is 72. Ignored with @samp{--html}. @item --footnote-style=@var{style} @itemx -s @var{style} @opindex --footnote-style=@var{style} @opindex -s @var{style} Set the footnote style to @var{style}, either @samp{end} for the end node style (the default) or @samp{separate} for the separate node style. The value set by this option overrides the value set in a Texinfo file by an @code{@@footnotestyle} command (@pxref{Footnotes}). When the footnote style is @samp{separate}, @code{makeinfo} makes a new node containing the footnotes found in the current node. When the footnote style is @samp{end}, @code{makeinfo} places the footnote references at the end of the current node. Ignored with @samp{--html}. @item --force @itemx -F @opindex --force @opindex -F Ordinarily, if the input file has errors, the output files are not created. With this option, they are preserved. @item --help @itemx -h @opindex --help @opindex -h Print a usage message listing all available options, then exit successfully. @item --html @opindex --html Generate HTML output rather than Info. @xref{Generating HTML}. By default, the HTML output is split into one output file per Texinfo source node, and the split output is written into a subdirectory with the name of the top-level info file. @item -I @var{dir} @opindex -I @var{dir} Append @var{dir} to the directory search list for finding files that are included using the @code{@@include} command. By default, @code{makeinfo} searches only the current directory. If @var{dir} is not given, the current directory @file{.} is appended. Note that @var{dir} can actually be a list of several directories separated by the usual path separator character (@samp{:} on Unix, @samp{;} on MS-DOS/MS-Windows). @item --ifdocbook @opindex --ifdocbook @itemx --ifhtml @opindex --ifhtml @itemx --ifinfo @opindex --ifinfo @itemx --ifplaintext @opindex --ifplaintext @itemx --iftex @opindex --iftex @itemx --ifxml @opindex --ifxml For the specified format, process @samp{@@if@var{format}} and @samp{@@@var{format}} commands even if not generating the given output format. For instance, if @option{--iftex} is specified, then @samp{@@iftex} and @samp{@@tex} blocks will be read. @item --macro-expand=@var{file} @itemx -E @var{file} @opindex --macro-expand=@var{file} @opindex -E @var{file} Output the Texinfo source with all the macros expanded to the named file. Normally, the results of macro expansion are used internally by @code{makeinfo} and then discarded. This option is used by @command{texi2dvi}. @item --no-headers @item --plaintext @opindex --no-headers @opindex --plaintext @cindex Plain text output @cindex ASCII text output @cindex Generating plain text files @cindex @file{INSTALL} file, generating @cindex Node separators, omitting @cindex Menus, omitting Do not include menus or node separator lines in the output, and implicitly @option{--enable-encoding} (see above). This results in a simple plain text file that you can (for example) send in email without complications, or include in a distribution (as in an @file{INSTALL} file). @cindex Navigation links, omitting For HTML output, likewise omit menus. And if @samp{--no-split} is also specified, do not include a navigation links at the top of each node (these are never included in the default case of split output). @xref{Generating HTML}. In both cases, ignore @code{@@setfilename} and write to standard output by default---can be overridden with @option{-o}. @item --no-ifdocbook @opindex --no-ifdocbook @itemx --no-ifhtml @opindex --no-ifhtml @itemx --no-ifinfo @opindex --no-ifinfo @itemx --no-ifplaintext @opindex --no-ifplaintext @itemx --no-iftex @opindex --no-iftex @itemx --no-ifxml @opindex --no-ifxml Do not process @samp{@@if@var{format}} and @samp{@@@var{format}} commands, and do process @samp{@@ifnot@var{format}}, even if generating the given format. For instance, if @option{--no-ifhtml} is specified, then @samp{@@ifhtml} and @samp{@@html} blocks will not be read, and @samp{@@ifnothtml} blocks will be. @item --no-number-footnotes @opindex --no-number-footnotes Suppress automatic footnote numbering. By default, @code{makeinfo} numbers each footnote sequentially in a single node, resetting the current footnote number to 1 at the start of each node. @item --no-number-sections @opindex --no-number-sections Do not output chapter, section, and appendix numbers. You need to specify this if your manual is not hierarchically-structured. @item --no-split @opindex --no-split @cindex Splitting of output files @cindex Output file splitting Suppress the splitting stage of @code{makeinfo}. By default, large output files (where the size is greater than 70k bytes) are split into smaller subfiles. For Info output, each one is approximately 50k bytes. For HTML output, each file contains one node (@pxref{Generating HTML}). @item --no-pointer-validate @itemx --no-validate @opindex --no-pointer-validate @opindex --no-validate @cindex Pointer validation, suppressing Suppress the pointer-validation phase of @code{makeinfo}---a dangerous thing to do. This can also be done with the @code{@@novalidate} command (@pxref{Use TeX,,Use @TeX{}}). Normally, after a Texinfo file is processed, some consistency checks are made to ensure that cross references can be resolved, etc. @xref{Pointer Validation}. @item --no-warn @opindex --no-warn Suppress warning messages (but @emph{not} error messages). @item --number-sections @opindex --number-sections Output chapter, section, and appendix numbers as in printed manuals. This is the default. It works only with hierarchically-structured manuals. @item --output=@var{file} @itemx -o @var{file} @opindex --output=@var{file} @opindex -o @var{file} Specify that the output should be directed to @var{file} and not to the file name specified in the @code{@@setfilename} command found in the Texinfo source (@pxref{setfilename}). If @var{file} is @samp{-}, output goes to standard output and @samp{--no-split} is implied. For split HTML output, @var{file} is the name for the directory into which all HTML nodes are written (@pxref{Generating HTML}). @item -P @var{dir} @opindex -P @var{dir} Prepend @var{dir} to the directory search list for @code{@@include}. If @var{dir} is not given, the current directory @file{.} is prepended. See @samp{-I} for more details. @item --paragraph-indent=@var{indent} @itemx -p @var{indent} @opindex --paragraph-indent=@var{indent} @opindex -p @var{indent} Set the paragraph indentation style to @var{indent}. The value set by this option overrides the value set in a Texinfo file by an @code{@@paragraphindent} command (@pxref{paragraphindent}). The value of @var{indent} is interpreted as follows: @table @asis @item @samp{asis} Preserve any existing indentation at the starts of paragraphs. @item @samp{0} or @samp{none} Delete any existing indentation. @item @var{num} Indent each paragraph by @var{num} spaces. @end table @item --reference-limit=@var{limit} @itemx -r @var{limit} @opindex --reference-limit=@var{limit} @opindex -r @var{limit} Set the value of the number of references to a node that @code{makeinfo} will make without reporting a warning. If a node has more than this number of references in it, @code{makeinfo} will make the references but also report a warning. The default is 1000. @item --split-size=@var{num} @opindex --split-size=@var{num} Keep Info files to at most @var{num} characters; default is 300,000. @item -U @var{var} Cause @var{var} to be undefined. This is equivalent to @code{@@clear @var{var}} in the Texinfo file (@pxref{set clear value}). @item --verbose @opindex --verbose Cause @code{makeinfo} to display messages saying what it is doing. Normally, @code{makeinfo} only outputs messages if there are errors or warnings. @item --version @itemx -V @opindex --version @opindex -V Print the version number, then exit successfully. @item --xml @opindex --xml Generate XML output rather than Info. @end table @vindex TEXINFO_OUTPUT_FORMAT @cindex Environment variable @code{TEXINFO_OUTPUT_FORMAT} @command{makeinfo} also reads the environment variable @env{TEXINFO_OUTPUT_FORMAT} to determine the output format, if not overridden by a command line option. The possible values are: @example docbook html info plaintext xml @end example If not set, Info output is the default. @node Pointer Validation @subsection Pointer Validation @cindex Pointer validation with @code{makeinfo} @cindex Validation of pointers If you do not suppress pointer validation with the @samp{--no-validate} option or the @code{@@novalidate} command in the source file (@pxref{Use TeX,,Use @TeX{}}), @code{makeinfo} will check the validity of the final Info file. Mostly, this means ensuring that nodes you have referenced really exist. Here is a complete list of what is checked: @enumerate @item If a `Next', `Previous', or `Up' node reference is a reference to a node in the current file and is not an external reference such as to @file{(dir)}, then the referenced node must exist.@refill @item In every node, if the `Previous' node is different from the `Up' node, then the node pointed to by the `Previous' field must have a `Next' field which points back to this node.@refill @item Every node except the `Top' node must have an `Up' pointer.@refill @item The node referenced by an `Up' pointer must itself reference the current node through a menu item, unless the node referenced by `Up' has the form `(@var{file})'. @item If the `Next' reference of a node is not the same as the `Next' reference of the `Up' reference, then the node referenced by the `Next' pointer must have a `Previous' pointer that points back to the current node. This rule allows the last node in a section to point to the first node of the next chapter.@refill @item Every node except `Top' should be referenced by at least one other node, either via the `Previous' or `Next' links, or via a menu or a cross-reference.@refill @end enumerate @cindex @@-commands in @@node, limited support Some Texinfo documents might fail during the validation phase because they use commands like @code{@@value} and @code{@@definfoenclose} in node definitions and cross-references inconsistently. (Your best bet is to avoid using @@-commands in node names.) Consider the following example: @example @group @@set nodename Node 1 @@node @@value@{nodename@}, Node 2, Top, Top This is node 1. @@node Node 2, , Node 1, Top This is node 2. @end group @end example @noindent Here, the node ``Node 1'' was referenced both verbatim and through @code{@@value}. By default, @code{makeinfo} fails such cases, because node names are not fully expanded until they are written to the output file. You should always try to reference nodes consistently; e.g., in the above example, the second @code{@@node} line should have also used @code{@@value}. However, if, for some reason, you @emph{must} reference node names inconsistently, and @code{makeinfo} fails to validate the file, you can use the @samp{--commands-in-node-names} option to force @code{makeinfo} to perform the expensive expansion of all node names it finds in the document. This might considerably slow down the program, though; twofold increase in conversion time was measured for large documents such as the Jargon file. @cindex @@value in @@node lines The support for @code{@@}-commands in @code{@@node} directives is not general enough to be freely used. For example, if the example above redefined @code{nodename} somewhere in the document, @code{makeinfo} will fail to convert it, even if invoked with the @samp{--commands-in-node-names} option. @samp{--commands-in-node-names} has no effect if the @samp{--no-validate} option is given. @node makeinfo in Emacs @subsection Running @code{makeinfo} Within Emacs @cindex Running @code{makeinfo} in Emacs @cindex @code{makeinfo} inside Emacs @cindex Shell, running @code{makeinfo} in You can run @code{makeinfo} in GNU Emacs Texinfo mode by using either the @code{makeinfo-region} or the @code{makeinfo-buffer} commands. In Texinfo mode, the commands are bound to @kbd{C-c C-m C-r} and @kbd{C-c C-m C-b} by default.@refill @table @kbd @item C-c C-m C-r @itemx M-x makeinfo-region Format the current region for Info.@refill @findex makeinfo-region @item C-c C-m C-b @itemx M-x makeinfo-buffer Format the current buffer for Info.@refill @findex makeinfo-buffer @end table When you invoke @code{makeinfo-region} the output goes to a temporary buffer. When you invoke @code{makeinfo-buffer} output goes to the file set with @code{@@setfilename} (@pxref{setfilename}). The Emacs @code{makeinfo-region} and @code{makeinfo-buffer} commands run the @code{makeinfo} program in a temporary shell buffer. If @code{makeinfo} finds any errors, Emacs displays the error messages in the temporary buffer.@refill @cindex Errors, parsing @cindex Parsing errors @findex next-error You can parse the error messages by typing @kbd{C-x `} (@code{next-error}). This causes Emacs to go to and position the cursor on the line in the Texinfo source that @code{makeinfo} thinks caused the error. @xref{Compilation, , Running @code{make} or Compilers Generally, emacs, The GNU Emacs Manual}, for more information about using the @code{next-error} command.@refill In addition, you can kill the shell in which the @code{makeinfo} command is running or make the shell buffer display its most recent output.@refill @table @kbd @item C-c C-m C-k @itemx M-x makeinfo-kill-job @findex makeinfo-kill-job Kill the current running @code{makeinfo} job (from @code{makeinfo-region} or @code{makeinfo-buffer}).@refill @item C-c C-m C-l @itemx M-x makeinfo-recenter-output-buffer @findex makeinfo-recenter-output-buffer Redisplay the @code{makeinfo} shell buffer to display its most recent output.@refill @end table @noindent (Note that the parallel commands for killing and recentering a @TeX{} job are @kbd{C-c C-t C-k} and @kbd{C-c C-t C-l}. @xref{Texinfo Mode Printing}.)@refill You can specify options for @code{makeinfo} by setting the @code{makeinfo-options} variable with either the @kbd{M-x customize} or the @kbd{M-x set-variable} command, or by setting the variable in your @file{.emacs} initialization file. For example, you could write the following in your @file{.emacs} file:@refill @example @group (setq makeinfo-options "--paragraph-indent=0 --no-split --fill-column=70 --verbose") @end group @end example @noindent @c If you write these three cross references using xref, you see @c three references to the same named manual, which looks strange. @iftex For more information, see @ref{makeinfo options, , Options for @code{makeinfo}}, as well as ``Easy Customization Interface,'' ``Examining and Setting Variables,'' and ``Init File'' in @cite{The GNU Emacs Manual}. @end iftex @ifnottex For more information, see@* @ref{Easy Customization, , Easy Customization Interface, emacs, The GNU Emacs Manual},@* @ref{Examining, , Examining and Setting Variables, emacs, The GNU Emacs Manual},@* @ref{Init File, , , emacs, The GNU Emacs Manual}, and@* @ref{makeinfo options, , Options for @code{makeinfo}}. @end ifnottex @node texinfo-format commands @subsection The @code{texinfo-format@dots{}} Commands In GNU Emacs in Texinfo mode, you can format part or all of a Texinfo file with the @code{texinfo-format-region} command. This formats the current region and displays the formatted text in a temporary buffer called @samp{*Info Region*}.@refill Similarly, you can format a buffer with the @code{texinfo-format-buffer} command. This command creates a new buffer and generates the Info file in it. Typing @kbd{C-x C-s} will save the Info file under the name specified by the @code{@@setfilename} line which must be near the beginning of the Texinfo file.@refill @table @kbd @item C-c C-e C-r @itemx @code{texinfo-format-region} @findex texinfo-format-region Format the current region for Info. @item C-c C-e C-b @itemx @code{texinfo-format-buffer} @findex texinfo-format-buffer Format the current buffer for Info. @end table The @code{texinfo-format-region} and @code{texinfo-format-buffer} commands provide you with some error checking, and other functions can provide you with further help in finding formatting errors. These procedures are described in an appendix; see @ref{Catching Mistakes}. However, the @code{makeinfo} program is often faster and provides better error checking (@pxref{makeinfo in Emacs}).@refill @node Batch Formatting @comment node-name, next, previous, up @subsection Batch Formatting @cindex Batch formatting for Info @cindex Info batch formatting You can format Texinfo files for Info using @code{batch-texinfo-format} and Emacs Batch mode. You can run Emacs in Batch mode from any shell, including a shell inside of Emacs. (@xref{Command Arguments,,, emacs, The GNU Emacs Manual}.) Here is a shell command to format all the files that end in @file{.texinfo} in the current directory: @example emacs -batch -funcall batch-texinfo-format *.texinfo @end example @noindent Emacs processes all the files listed on the command line, even if an error occurs while attempting to format some of them.@refill Run @code{batch-texinfo-format} only with Emacs in Batch mode as shown; it is not interactive. It kills the Batch mode Emacs on completion.@refill @code{batch-texinfo-format} is convenient if you lack @code{makeinfo} and want to format several Texinfo files at once. When you use Batch mode, you create a new Emacs process. This frees your current Emacs, so you can continue working in it. (When you run @code{texinfo-format-region} or @code{texinfo-format-buffer}, you cannot use that Emacs for anything else until the command finishes.)@refill @node Tag and Split Files @comment node-name, next, previous, up @subsection Tag Files and Split Files @cindex Making a tag table automatically @cindex Tag table, making automatically If a Texinfo file has more than 30,000 bytes, @code{texinfo-format-buffer} automatically creates a tag table for its Info file; @code{makeinfo} always creates a tag table. With a @dfn{tag table}, Info can jump to new nodes more quickly than it can otherwise.@refill @cindex Indirect subfiles In addition, if the Texinfo file contains more than about 300,000 bytes, @code{texinfo-format-buffer} and @code{makeinfo} split the large Info file into shorter @dfn{indirect} subfiles of about 300,000 bytes each. Big files are split into smaller files so that Emacs does not need to make a large buffer to hold the whole of a large Info file; instead, Emacs allocates just enough memory for the small, split-off file that is needed at the time. This way, Emacs avoids wasting memory when you run Info. (Before splitting was implemented, Info files were always kept short and @dfn{include files} were designed as a way to create a single, large printed manual out of the smaller Info files. @xref{Include Files}, for more information. Include files are still used for very large documents, such as @cite{The Emacs Lisp Reference Manual}, in which each chapter is a separate file.)@refill When a file is split, Info itself makes use of a shortened version of the original file that contains just the tag table and references to the files that were split off. The split-off files are called @dfn{indirect} files.@refill The split-off files have names that are created by appending @w{@samp{-1}}, @w{@samp{-2}}, @w{@samp{-3}} and so on to the file name specified by the @code{@@setfilename} command. The shortened version of the original file continues to have the name specified by @code{@@setfilename}.@refill At one stage in writing this document, for example, the Info file was saved as the file @file{test-texinfo} and that file looked like this:@refill @example @group Info file: test-texinfo, -*-Text-*- produced by texinfo-format-buffer from file: new-texinfo-manual.texinfo ^_ Indirect: test-texinfo-1: 102 test-texinfo-2: 50422 @end group @group test-texinfo-3: 101300 ^_^L Tag table: (Indirect) Node: overview^?104 Node: info file^?1271 @end group @group Node: printed manual^?4853 Node: conventions^?6855 @dots{} @end group @end example @noindent (But @file{test-texinfo} had far more nodes than are shown here.) Each of the split-off, indirect files, @file{test-texinfo-1}, @file{test-texinfo-2}, and @file{test-texinfo-3}, is listed in this file after the line that says @samp{Indirect:}. The tag table is listed after the line that says @samp{Tag table:}. @refill In the list of indirect files, the number following the file name records the cumulative number of bytes in the preceding indirect files, not counting the file list itself, the tag table, or the permissions text in each file. In the tag table, the number following the node name records the location of the beginning of the node, in bytes from the beginning of the (unsplit) output. If you are using @code{texinfo-format-buffer} to create Info files, you may want to run the @code{Info-validate} command. (The @code{makeinfo} command does such a good job on its own, you do not need @code{Info-validate}.) However, you cannot run the @kbd{M-x Info-validate} node-checking command on indirect files. For information on how to prevent files from being split and how to validate the structure of the nodes, see @ref{Using Info-validate}. @node Installing an Info File @section Installing an Info File @cindex Installing an Info file @cindex Info file installation @cindex @file{dir} directory for Info installation Info files are usually kept in the @file{info} directory. You can read Info files using the standalone Info program or the Info reader built into Emacs. (@inforef{Top, info, info}, for an introduction to Info.) @menu * Directory File:: The top level menu for all Info files. * New Info File:: Listing a new Info file. * Other Info Directories:: How to specify Info files that are located in other directories. * Installing Dir Entries:: How to specify what menu entry to add to the Info directory. * Invoking install-info:: @code{install-info} options. @end menu @node Directory File @subsection The Directory File @file{dir} For Info to work, the @file{info} directory must contain a file that serves as a top level directory for the Info system. By convention, this file is called @file{dir}. (You can find the location of this file within Emacs by typing @kbd{C-h i} to enter Info and then typing @kbd{C-x C-f} to see the pathname to the @file{info} directory.) The @file{dir} file is itself an Info file. It contains the top level menu for all the Info files in the system. The menu looks like this:@refill @example @group * Menu: * Info: (info). Documentation browsing system. * Emacs: (emacs). The extensible, self-documenting text editor. * Texinfo: (texinfo). With one source file, make either a printed manual using @@TeX@{@} or an Info file. @dots{} @end group @end example Each of these menu entries points to the `Top' node of the Info file that is named in parentheses. (The menu entry does not need to specify the `Top' node, since Info goes to the `Top' node if no node name is mentioned. @xref{Other Info Files, , Nodes in Other Info Files}.)@refill Thus, the @samp{Info} entry points to the `Top' node of the @file{info} file and the @samp{Emacs} entry points to the `Top' node of the @file{emacs} file.@refill In each of the Info files, the `Up' pointer of the `Top' node refers back to the @code{dir} file. For example, the line for the `Top' node of the Emacs manual looks like this in Info:@refill @example File: emacs Node: Top, Up: (DIR), Next: Distrib @end example @noindent In this case, the @file{dir} file name is written in upper case letters---it can be written in either upper or lower case. This is not true in general, it is a special case for @file{dir}. @node New Info File @subsection Listing a New Info File @cindex Adding a new Info file @cindex Listing a new Info file @cindex New Info file, listing it in @file{dir} file @cindex Info file, listing a new @cindex @file{dir} file listing To add a new Info file to your system, you must write a menu entry to add to the menu in the @file{dir} file in the @file{info} directory. For example, if you were adding documentation for GDB, you would write the following new entry:@refill @example * GDB: (gdb). The source-level C debugger. @end example @noindent The first part of the menu entry is the menu entry name, followed by a colon. The second part is the name of the Info file, in parentheses, followed by a period. The third part is the description. The name of an Info file often has a @file{.info} extension. Thus, the Info file for GDB might be called either @file{gdb} or @file{gdb.info}. The Info reader programs automatically try the file name both with and without @file{.info}@footnote{On MS-DOS/MS-Windows systems, Info will try the @file{.inf} extension as well.}; so it is better to avoid clutter and not to write @samp{.info} explicitly in the menu entry. For example, the GDB menu entry should use just @samp{gdb} for the file name, not @samp{gdb.info}. @node Other Info Directories @subsection Info Files in Other Directories @cindex Installing Info in another directory @cindex Info installed in another directory @cindex Another Info directory @cindex @file{dir} files and Info directories If an Info file is not in the @file{info} directory, there are three ways to specify its location:@refill @enumerate @item Write the pathname in the @file{dir} file as the second part of the menu. @item If you are using Emacs, list the name of the file in a second @file{dir} file, in its directory; and then add the name of that directory to the @code{Info-directory-list} variable in your personal or site initialization file. This variable tells Emacs where to look for @file{dir} files (the files must be named @file{dir}). Emacs merges the files named @file{dir} from each of the listed directories. (In Emacs version 18, you can set the @code{Info-directory} variable to the name of only one directory.)@refill @item Specify the Info directory name in the @code{INFOPATH} environment variable in your @file{.profile} or @file{.cshrc} initialization file. (Only you and others who set this environment variable will be able to find Info files whose location is specified this way.) @end enumerate For example, to reach a test file in the @file{/home/bob/info} directory, you could add an entry like this to the menu in the standard @file{dir} file:@refill @example * Test: (/home/bob/info/info-test). Bob's own test file. @end example @noindent In this case, the absolute file name of the @file{info-test} file is written as the second part of the menu entry.@refill Alternatively, you could write the following in your @file{.emacs} file: @vindex Info-directory-list @example @group (require 'info) (setq Info-directory-list (cons (expand-file-name "/home/bob/info") Info-directory-list)) @end group @end example This tells Emacs to merge the system @file{dir} file with the @file{dir} file in @file{/home/bob/info}. Thus, Info will list the @file{/home/bob/info/info-test} file as a menu entry in the @file{/home/bob/info/dir} file. Emacs does the merging only when @kbd{M-x info} is first run, so if you want to set @code{Info-directory-list} in an Emacs session where you've already run @code{info}, you must @code{(setq Info-dir-contents nil)} to force Emacs to recompose the @file{dir} file. @vindex INFOPATH @cindex Environment variable @code{INFOPATH} Finally, you can tell Info where to look by setting the @code{INFOPATH} environment variable in your shell startup file, such as @file{.cshrc}, @file{.profile} or @file{autoexec.bat}. If you use a Bourne-compatible shell such as @code{sh} or @code{bash} for your shell command interpreter, you set the @code{INFOPATH} environment variable in the @file{.profile} initialization file; but if you use @code{csh} or @code{tcsh}, you set the variable in the @file{.cshrc} initialization file. On MS-DOS/MS-Windows systems, you must set @code{INFOPATH} in your @file{autoexec.bat} file or in the Registry. Each type of shell uses a different syntax. @itemize @bullet @item In a @file{.cshrc} file, you could set the @code{INFOPATH} variable as follows:@refill @smallexample setenv INFOPATH .:~/info:/usr/local/emacs/info @end smallexample @item In a @file{.profile} file, you would achieve the same effect by writing:@refill @smallexample INFOPATH=.:$HOME/info:/usr/local/emacs/info export INFOPATH @end smallexample @item @pindex autoexec.bat In a @file{autoexec.bat} file, you write this command@footnote{Note the use of @samp{;} as the directory separator, and a different syntax for using values of other environment variables.}: @smallexample set INFOPATH=.;%HOME%/info;c:/usr/local/emacs/info @end smallexample @end itemize @noindent The @samp{.} indicates the current directory as usual. Emacs uses the @code{INFOPATH} environment variable to initialize the value of Emacs's own @code{Info-directory-list} variable. The stand-alone Info reader merges any files named @file{dir} in any directory listed in the @env{INFOPATH} variable into a single menu presented to you in the node called @samp{(dir)Top}. @cindex Colon, last in @env{INFOPATH} However you set @env{INFOPATH}, if its last character is a colon@footnote{On MS-DOS/MS-Windows systems, use semi-colon instead.}, this is replaced by the default (compiled-in) path. This gives you a way to augment the default path with new directories without having to list all the standard places. For example (using @code{sh} syntax): @example INFOPATH=/local/info: export INFOPATH @end example @noindent will search @file{/local/info} first, then the standard directories. Leading or doubled colons are not treated specially. @cindex @file{dir} file, creating your own When you create your own @file{dir} file for use with @code{Info-directory-list} or @env{INFOPATH}, it's easiest to start by copying an existing @file{dir} file and replace all the text after the @samp{* Menu:} with your desired entries. That way, the punctuation and special CTRL-_ characters that Info needs will be present. @node Installing Dir Entries @subsection Installing Info Directory Files When you install an Info file onto your system, you can use the program @code{install-info} to update the Info directory file @file{dir}. Normally the makefile for the package runs @code{install-info}, just after copying the Info file into its proper installed location. @findex dircategory @findex direntry In order for the Info file to work with @code{install-info}, you include the commands @code{@@dircategory} and @code{@@direntry}@dots{}@code{@@end direntry} in the Texinfo source file. Use @code{@@direntry} to specify the menu entries to add to the Info directory file, and use @code{@@dircategory} to specify which part of the Info directory to put it in. Here is how these commands are used in this manual: @smallexample @@dircategory Texinfo documentation system @@direntry * Texinfo: (texinfo). The GNU documentation format. * install-info: (texinfo)Invoking install-info. @dots{} @dots{} @@end direntry @end smallexample Here's what this produces in the Info file: @smallexample INFO-DIR-SECTION Texinfo documentation system START-INFO-DIR-ENTRY * Texinfo: (texinfo). The GNU documentation format. * install-info: (texinfo)Invoking install-info. @dots{} @dots{} END-INFO-DIR-ENTRY @end smallexample @noindent The @code{install-info} program sees these lines in the Info file, and that is how it knows what to do. Always use the @code{@@direntry} and @code{@@dircategory} commands near the beginning of the Texinfo input, before the first @code{@@node} command. If you use them later on in the input, @code{install-info} will not notice them. If you use @code{@@dircategory} more than once in the Texinfo source, each usage specifies the `current' category; any subsequent @code{@@direntry} commands will add to that category. @cindex Free Software Directory @cindex Dir categories, choosing @cindex Categories, choosing When choosing a category name for the @code{@@dircategory} command, we recommend consulting the @uref{http://www.gnu.org/directory, Free Software Directory}. If your program is not listed there, or listed incorrectly or incompletely, please report the situation to the directory maintainers (@email{bug-directory@@gnu.org}) so that the category names can be kept in sync. Here are a few examples (see the @file{util/dir-example} file in the Texinfo distribution for large sample @code{dir} file): @display Emacs Localization Printing Software development Software libraries Text creation and manipulation @end display @cindex Invoking nodes, including in dir file Each `Invoking' node for every program installed should have a corresponding @code{@@direntry}. This lets users easily find the documentation for the different programs they can run, as with the traditional @command{man} system. @node Invoking install-info @subsection Invoking @command{install-info} @pindex install-info @code{install-info} inserts menu entries from an Info file into the top-level @file{dir} file in the Info system (see the previous sections for an explanation of how the @file{dir} file works). It's most often run as part of software installation, or when constructing a @file{dir} file for all manuals on a system. Synopsis: @example install-info [@var{option}]@dots{} [@var{info-file} [@var{dir-file}]] @end example If @var{info-file} or @var{dir-file} are not specified, the options (described below) that define them must be. There are no compile-time defaults, and standard input is never used. @code{install-info} can read only one Info file and write only one @file{dir} file per invocation. @cindex @file{dir}, created by @code{install-info} If @var{dir-file} (however specified) does not exist, @code{install-info} creates it if possible (with no entries). @cindex Compressed files, reading @cindex Dir files, compressed If any input file is compressed with @code{gzip} (@pxref{Invoking gzip,,,gzip, Gzip}), @code{install-info} automatically uncompresses it for reading. And if @var{dir-file} is compressed, @code{install-info} also automatically leaves it compressed after writing any changes. If @var{dir-file} itself does not exist, @code{install-info} tries to open @file{@var{dir-file}.gz}. Options: @table @code @item --delete @opindex --delete Delete the entries in @var{info-file} from @var{dir-file}. The file name in the entry in @var{dir-file} must be @var{info-file} (except for an optional @samp{.info} in either one). Don't insert any new entries. @item --dir-file=@var{name} @itemx -d @var{name} @opindex --dir-file=@var{name} @opindex -d @var{name} Specify file name of the Info directory file. This is equivalent to using the @var{dir-file} argument. @item --entry=@var{text} @itemx -e @var{text} @opindex --entry=@var{text} @opindex -e @var{text} Insert @var{text} as an Info directory entry; @var{text} should have the form of an Info menu item line plus zero or more extra lines starting with whitespace. If you specify more than one entry, they are all added. If you don't specify any entries, they are determined from information in the Info file itself. @item --help @itemx -h @opindex --help @opindex -h Display a usage message listing basic usage and all available options, then exit successfully. @item --info-file=@var{file} @itemx -i @var{file} @opindex --info-file=@var{file} @opindex -i @var{file} Specify Info file to install in the directory. Equivalent to using the @var{info-file} argument. @item --info-dir=@var{dir} @itemx -D @var{dir} @opindex --info-dir=@var{dir} @opindex -D @var{dir} Specify the directory where the directory file @file{dir} resides. Equivalent to @samp{--dir-file=@var{dir}/dir}. @item --item=@var{text} @opindex --item=@var{text} Same as @samp{--entry=@var{text}}. An Info directory entry is actually a menu item. @item --quiet @opindex --quiet Suppress warnings. @item --remove @itemx -r @opindex --remove @opindex -r Same as @samp{--delete}. @item --section=@var{sec} @itemx -s @var{sec} @opindex --section=@var{sec} @opindex -s @var{sec} Put this file's entries in section @var{sec} of the directory. If you specify more than one section, all the entries are added in each of the sections. If you don't specify any sections, they are determined from information in the Info file itself. @item --version @itemx -V @opindex --version @opindex -V @cindex Version number, for install-info Display version information and exit successfully. @end table @node Generating HTML @chapter Generating HTML @cindex HTML output @command{makeinfo} generates Info output by default, but given the @option{--html} option, it will generate HTML, for web browsers and other programs. This chapter gives some details on such HTML output. @command{makeinfo} can also write in XML and Docbook format, but we do not as yet describe these further. @xref{Output Formats}, for a brief overview of all the output formats. @menu * HTML Translation:: Details of the HTML output. * HTML Splitting:: How HTML output is split. * HTML CSS:: Influencing HTML output with Cascading Style Sheets. * HTML Xref:: Cross-references in HTML output. @end menu @node HTML Translation @section HTML Translation @command{makeinfo} will include segments of Texinfo source between @code{@@ifhtml} and @code{@@end ifhtml} in the HTML output (but not any of the other conditionals, by default). Source between @code{@@html} and @code{@@end html} is passed without change to the output (i.e., suppressing the normal escaping of input @samp{<}, @samp{>} and @samp{&} characters which have special significance in HTML). @xref{Conditional Commands}. @opindex --footnote-style@r{, ignored in HTML output} The @option{--footnote-style} option is currently ignored for HTML output; footnotes are always linked to the end of the output file. @cindex Navigation bar, in HTML output By default, a navigation bar is inserted at the start of each node, analogous to Info output. The @samp{--no-headers} option suppresses this if used with @samp{--no-split}. Header @code{<link>} elements in split output can support info-like navigation with browsers like Lynx and @w{Emacs W3} which implement this HTML@tie{}1.0 feature. @cindex HTML output, browser compatibility of The HTML generated is mostly standard (i.e., HTML@tie{}2.0, RFC-1866). One exception is that HTML@tie{}3.2 tables are generated from the @code{@@multitable} command, but tagged to degrade as well as possible in browsers without table support. The HTML@tie{}4 @samp{lang} attribute on the @samp{<html>} attribute is also used. (Please report output from an error-free run of @code{makeinfo} which has browser portability problems as a bug.) @node HTML Splitting @section HTML Splitting @cindex Split HTML output @cindex HTML output, split When splitting output (which is the default), @command{makeinfo} writes HTML output into (generally) one output file per Texinfo source @code{@@node}. The output file name is the node name with special characters replaced by @samp{-}'s, so it can work as a filename. In the unusual case of two different nodes having the same name after this treatment, they are written consecutively to the same file, with HTML anchors so each can be referred to separately. If @command{makeinfo} is run on a system which does not distinguish case in filenames, nodes which are the same except for case will also be folded into the same output file. When splitting, the HTML output files are written into a subdirectory, with the name chosen as follows: @enumerate @item @command{makeinfo} first tries the subdirectory with the base name from @code{@@setfilename} (that is, any extension is removed). For example, HTML output for @code{@@setfilename gcc.info} would be written into a subdirectory named @samp{gcc}. @item If that directory cannot be created for any reason, then @command{makeinfo} tries appending @samp{.html} to the directory name. For example, output for @code{@@setfilename texinfo} would be written to @samp{texinfo.html}. @item If the @samp{@var{name}.html} directory can't be created either, @code{makeinfo} gives up. @end enumerate @noindent In any case, the top-level output file within the directory is always named @samp{index.html}. Monolithic output (@code{--no-split}) is named according to @code{@@setfilename} (with any @samp{.info} extension is replaced with @samp{.html}) or @code{--output} (the argument is used literally). @node HTML CSS @section HTML CSS @cindex HTML, and CSS @cindex CSS, and HTML output @cindex Cascading Style Sheets, and HTML output Cascading Style Sheets (CSS for short) is an Internet standard for influencing the display of HTML documents: see @uref{http://www.w3.org/Style/CSS/}. By default, @command{makeinfo} includes a few simple CSS commands to better implement the appearance of some of the environments. Here are two of them, as an example: @example pre.display @{ font-family:inherit @} pre.smalldisplay @{ font-family:inherit; font-size:smaller @} @end example A full explanation of CSS is (far) beyond this manual; please see the reference above. In brief, however, this specification tells the web browser to use a `smaller' font size for @code{@@smalldisplay} text, and to use the `inherited' font (generally a regular roman typeface) for both @code{@@smalldisplay} and @code{@@display}. By default, the HTML @samp{<pre>} command uses a monospaced font. You can influence the CSS in the HTML output with the @option{--css-include=@var{file}} option to @command{makeinfo}. This includes the contents @var{file} in the HTML output, as you might expect. However, the details are somewhat tricky, as described in the following, to provide maximum flexibility. @cindex @@import specifications, in CSS files The CSS file may begin with so-called @samp{@@import} directives, which link to external CSS specifications for browsers to use when interpreting the document. Again, a full description is beyond our scope here, but we'll describe how they work syntactically, so we can explain how @command{makeinfo} handles them. @cindex Comments, in CSS files There can be more than one @samp{@@import}, but they have to come first in the file, with only whitespace and comments interspersed, no normal definitions. (Technical exception: an @samp{@@charset} directive may precede the @samp{@@import}'s. This does not alter @command{makeinfo}'s behavior, it just copies the @samp{@@charset} if present.) Comments in CSS files are delimited by @samp{/* ... */}, as in C. An @samp{@@import} directive must be in one of these two forms: @example @@import url(http://example.org/foo.css); @@import "http://example.net/bar.css"; @end example As far as @command{makeinfo} is concerned, the crucial characters are the @samp{@@} at the beginning and the semicolon terminating the directive. When reading the CSS file, it simply copies any such @samp{@@}-directive into the output, as follows: @itemize @item If @var{file} contains only normal CSS declarations, it is included after @command{makeinfo}'s default CSS, thus overriding it. @item If @var{file} begins with @samp{@@import} specifications (see below), then the @samp{import}'s are included first (they have to come first, according to the standard), and then @command{makeinfo}'s default CSS is included. If you need to override @command{makeinfo}'s defaults from an @samp{@@import}, you can do so with the @samp{!@: important} CSS construct, as in: @example pre.smallexample @{ font-size: inherit ! important @} @end example @item If @var{file} contains both @samp{@@import} and inline CSS specifications, the @samp{@@import}'s are included first, then @command{makeinfo}'s defaults, and lastly the inline CSS from @var{file}. @item Any @@-directive other than @samp{@@import} and @samp{@@charset} is treated as a CSS declaration, meaning @command{makeinfo} includes its default CSS and then the rest of the file. @end itemize If the CSS file is malformed or erroneous, @command{makeinfo}'s output is unspecified. @command{makeinfo} does not try to interpret the meaning of the CSS file in any way; it just looks for the special @samp{@@} and @samp{;} characters and blindly copies the text into the output. Comments in the CSS file may or may not be included in the output. @node HTML Xref @section HTML Cross-references @cindex HTML cross-references @cindex Cross-references, in HTML output Cross-references between Texinfo manuals in HTML format amount, in the end, to a standard HTML @code{<a>} link, but the details are unfortunately complex. This section describes the algorithm used in detail, so that Texinfo can cooperate with other programs, such as @command{texi2html}, by writing mutually compatible HTML files. This algorithm may or may not be used for links @emph{within} HTML output for a Texinfo file. Since no issues of compatibility arise in such cases, we do not need to specify this. We try to support references to such ``external'' manuals in both monolithic and split forms. A @dfn{monolithic} (mono) manual is entirely contained in one file, and a @dfn{split} manual has a file for each node. (@xref{HTML Splitting}.) @cindex Dumas, Patrice Acknowledgement: this algorithm was primarily devised by Patrice Dumas in 2003--04. @menu * Link Basics: HTML Xref Link Basics. * Node Expansion: HTML Xref Node Name Expansion. * Command Expansion: HTML Xref Command Expansion. * 8-bit Expansion: HTML Xref 8-bit Character Expansion. * Mismatch: HTML Xref Mismatch. @end menu @node HTML Xref Link Basics @subsection HTML Cross-reference Link Basics @cindex HTML cross-reference link basics For our purposes, an HTML link consists of four components: a host name, a directory part, a file part, and a target part. We always assume the @code{http} protocol. For example: @example http://@var{host}/@var{dir}/@var{file}.html#@var{target} @end example The information to construct a link comes from the node name and manual name in the cross-reference command in the Texinfo source (@pxref{Cross References}), and from @dfn{external information}, which is currently simply hardwired. In the future, it may come from an external data file. We now consider each part in turn. The @var{host} is hardwired to be the local host. This could either be the literal string @samp{localhost}, or, according to the rules for HTML links, the @samp{http://localhost/} could be omitted entirely. The @var{dir} and @var{file} parts are more complicated, and depend on the relative split/mono nature of both the manual being processed and the manual that the cross-reference refers to. The underlying idea is that there is one directory for Texinfo manuals in HTML, and each manual is either available as a monolithic file @file{manual.html}, or a split subdirectory @file{manual/*.html}. Here are the cases: @itemize @bullet @item If the present manual is split, and the referent manual is also split, the directory is @samp{../@var{referent/}} and the file is the expanded node name (described later). @item If the present manual is split, and the referent manual is mono, the directory is @samp{../} and the file is @file{@var{referent}.html}. @item If the present manual is mono, and the referent manual is split, the directory is @file{@var{referent}/} and the file is the expanded node name. @item If the present manual is mono, and the referent manual is also mono, the directory is @file{./} (or just the empty string), and the file is @file{@var{referent}.html}. @end itemize One exception: the algorithm for node name expansion prefixes the string @samp{g_t} when the node name begins with a non-letter. This kludge (due to XHTML rules) is not necessary for filenames, and is therefore omitted. Any directory part in the filename argument of the source cross-reference command is ignored. Thus, @code{@@xref@{,,,../foo@}} and @code{@@xref@{,,,foo@}} both use @samp{foo} as the manual name. This is because any such attempted hardwiring of the directory is very unlikely to be useful for both Info and HTML output. Finally, the @var{target} part is always the expanded node name. Whether the present manual is split or mono is determined by user option; @command{makeinfo} defaults to split, with the @option{--no-split} option overriding this. Whether the referent manual is split or mono is another bit of the external information. For now, @command{makeinfo} simply assumes the referent manual is the same as the present manual. There can be a mismatch between the format of the referent manual that the generating software assumes, and the format it's actually present in. @xref{HTML Xref Mismatch}. @node HTML Xref Node Name Expansion @subsection HTML Cross-reference Node Name Expansion @cindex HTML cross-reference node name expansion @cindex node name expansion, in HTML cross-references @cindex expansion, of node names in HTML cross-references As mentioned in the previous section, the key part of the HTML cross-reference algorithm is the conversion of node names in the Texinfo source into strings suitable for XHTML identifiers and filenames. The restrictions are similar for each: plain ASCII letters, numbers, and the @samp{-} and @samp{_} characters are all that can be used. (Although HTML anchors can contain most characters, XHTML is more restrictive.) Cross-references in Texinfo can actually refer either to nodes or anchors (@pxref{anchor}), but anchors are treated identically to nodes in this context, so we'll continue to say ``node'' names for simplicity. (@@-commands and 8-bit characters are not presently handled by @command{makeinfo} for HTML cross-references. See the next section.) A special exception: the Top node (@pxref{The Top Node}) is always mapped to the file @file{index.html}, to match web server software. However, the HTML @emph{target} is @samp{Top}. Thus (in the split case): @example @@xref@{Top, Introduction,, emacs, The GNU Emacs Manual@}. @result{} <a href="emacs/index.html#Top"> @end example @enumerate @item The standard ASCII letters (a-z and A-Z) are not modified. All other characters are changed as specified below. @item The standard ASCII numbers (0-9) are not modified except when a number is the first character of the node name. In that case, see below. @item Multiple consecutive space, tab and newline characters are transformed into just one space. (It's not possible to have newlines in node names with the current implementation, but we specify it anyway, just in case.) @item Leading and trailing spaces are removed. @item After the above has been applied, each remaining space character is converted into a @samp{-} character. @item Other ASCII 7-bit characters are transformed into @samp{_00@var{xx}}, where @var{xx} is the ASCII character code in (lowercase) hexadecimal. This includes @samp{_}, which is mapped to @samp{_005f}. @item If the node name does not begin with a letter, the literal string @samp{g_t} is prefixed to the result. (Due to the rules above, that string can never occur otherwise; it is an arbitrary choice, standing for ``GNU Texinfo''.) This is necessary because XHTML requires that identifiers begin with a letter. @end enumerate For example: @example @@node A node --- with _'% @result{} A-node-_002d_002d_002d-with-_005f_0027_0025 @end example Notice in particular: @itemize @bullet @item @samp{_} @result{} @samp{_005f} @item @samp{-} @result{} @samp{_002d} @item @samp{A node} @result{} @samp{A-node} @end itemize On case-folding computer systems, nodes differing only by case will be mapped to the same file. In particular, as mentioned above, Top always maps to the file @file{index.html}. Thus, on a case-folding system, Top and a node named `Index' will both be written to @file{index.html}. Fortunately, the targets serve to distinguish these cases, since HTML target names are always case-sensitive, independent of operating system. @node HTML Xref Command Expansion @subsection HTML Cross-reference Command Expansion @cindex HTML cross-reference command expansion In standard Texinfo, node names may not contain @@-commands. @command{makeinfo} has an option @option{--commands-in-node-names} which partially supports it (@pxref{Invoking makeinfo}), but it is not robust and not recommended. Thus, @command{makeinfo} also does not fully implement this part of the HTML cross-reference algorithm, but it is documented here for the sake of completeness. First, comments are removed. Next, any @code{@@value} commands (@pxref{set value}) and macro invocations (@pxref{Invoking Macros}) are fully expanded. Then, for the following commands, the command name and braces are removed, the text of the argument is recursively transformed: @example @@asis @@b @@cite @@code @@command @@dfn @@dmn @@dotless @@emph @@env @@file @@indicateurl @@kbd @@key @@samp @@sc @@slanted @@strong @@t @@var @@w @end example @noindent For @code{@@sc}, any letters are capitalized. The following commands are replaced by constant text, as shown. If any of these commands have non-empty arguments, as in @code{@@TeX@{bad@}}, it is an error, and the result is unspecified. `(space)' means a space character, `(nothing)' means the empty string, etc. The notation `U+@var{xxxx}' means Unicode code point @var{xxxx}. There are further transformations of many of these expansions for the final file or target name, such as space characters to @samp{-}, etc., according to the other rules. @multitable @columnfractions .3 .5 @item @code{@@(newline)} @tab (space) @item @code{@@(space)} @tab (space) @item @code{@@(tab)} @tab (space) @item @code{@@!} @tab @samp{!} @item @code{@@*} @tab (space) @item @code{@@-} @tab (nothing) @item @code{@@.} @tab @samp{.} @item @code{@@:} @tab (nothing) @item @code{@@?} @tab @samp{?} @item @code{@@@@} @tab @samp{@@} @item @code{@@@{} @tab @samp{@{} @item @code{@@@}} @tab @samp{@}} @item @code{@@LaTeX} @tab @samp{LaTeX} @item @code{@@TeX} @tab @samp{TeX} @item @code{@@bullet} @tab U+2022 @item @code{@@comma} @tab @samp{,} @item @code{@@copyright} @tab U+00A9 @item @code{@@dots} @tab U+2026 @item @code{@@enddots} @tab @samp{...} @item @code{@@equiv} @tab U+2261 @item @code{@@error} @tab @samp{error-->} @item @code{@@euro} @tab U+20AC @item @code{@@exclamdown} @tab U+00A1 @item @code{@@expansion} @tab U+2192 @item @code{@@minus} @tab U+2212 @item @code{@@ordf} @tab U+00AA @item @code{@@ordm} @tab U+00BA @item @code{@@point} @tab U+2217 @item @code{@@pounds} @tab U+00A3 @item @code{@@print} @tab @samp{-|} @item @code{@@questiondown} @tab U+00BF @item @code{@@registeredsymbol} @tab U+00AE @item @code{@@result} @tab U+21D2 @item @code{@@tie} @tab (space) @end multitable An @code{@@acronym} or @code{@@abbr} command is replaced by the first argument, followed by the second argument in parentheses, if present. @xref{acronym}. An @code{@@email} command is replaced by the @var{text} argument if present, else the address. @xref{email}. An @code{@@image} command is replaced by the filename (first) argument. @xref{Images}. A @code{@@verb} command is replaced by its transformed argument. @xref{verb}. Any other command is an error, and the result is unspecified. @node HTML Xref 8-bit Character Expansion @subsection HTML Cross-reference 8-bit Character Expansion @cindex HTML cross-reference 8-bit character expansion @cindex 8-bit characters, in HTML cross-references @cindex Expansion of 8-bit characters in HTML cross-references Usually, characters other than plain 7-bit ASCII are transformed into the corresponding Unicode code point(s) in Normalization Form C, which uses precomposed characters where available. (This is the normalization form recommended by the W3C and other bodies.) This holds when that code point is 0xffff or less, as it almost always is. These will then be further transformed by the rules above into the string @samp{_@var{xxxx}}, where @var{xxxx} is the code point in hex. For example, combining this rule and the previous section: @example @@node @@b@{A@} @@TeX@{@} @@u@{B@} @@point@{@}@@enddots@{@} @result{} A-TeX-B_0306-_2605_002e_002e_002e @end example Notice: 1)@tie{}@code{@@enddots} expands to three periods which in turn expands to three @samp{_002e}'s; 2)@tie{}@code{@@u@{B@}} is a `B' with a breve accent, which does not exist as a pre-accented Unicode character, therefore expands to @samp{B_0306} (B with combining breve). When the Unicode code point is above 0xffff, the transformation is @samp{__@var{xxxxxx}}, that is, two leading underscores followed by six hex digits. Since Unicode has declared that their highest code point is 0x10ffff, this is sufficient. (We felt it was better to define this extra escape than to always use six hex digits, since the first two would nearly always be zeros.) For the definition of Unicode Normalization Form C, see Unicode report UAX#15, @uref{http://www.unicode.org/reports/tr15/}. Many related documents and implementations are available elsewhere on the web. @node HTML Xref Mismatch @subsection HTML Cross-reference Mismatch @cindex HTML cross-reference mismatch @cindex Mismatched HTML cross-reference source and target As mentioned earlier (@pxref{HTML Xref Link Basics}), the generating software has to guess whether a given manual being cross-referenced is available in split or monolithic form---and, inevitably, it might guess wrong. However, it is possible when the referent manual itself is generated, it is possible to handle at least some mismatches. In the case where we assume the referent is split, but it is actually available in mono, the only recourse would be to generate a @file{manual/} subdirectory full of HTML files which redirect back to the monolithic @file{manual.html}. Since this is essentially the same as a split manual in the first place, it's not very appealing. On the other hand, in the case where we assume the referent is mono, but it is actually available in split, it is possible to use JavaScript to redirect from the putatively monolithic @file{manual.html} to the different @file{manual/node.html} files. Here's an example: @example function redirect() @{ switch (location.hash) @{ case "#Node1": location.replace("manual/Node1.html#Node1"); break; case "#Node2" : location.replace("manual/Node2.html#Node2"); break; @dots{} default:; @} @} @end example Then, in the @code{<body>} tag of @file{manual.html}: @example <body onLoad="redirect();"> @end example Once again, this is something the software which generated the @emph{referent} manual has to do in advance, it's not something the software generating the actual cross-reference in the present manual can control. Ultimately, we hope to allow for an external configuration file to control which manuals are available from where, and how. @ignore -- not yet -- external information -------------------- The information for the reference is searched in the file `htmlxref.cnf' present in the following directories: <srcdir>/.texinfo/, ~/.texinfo/, SYSCONFDIR/texinfo/, DATADIR/texinfo/ The first match should be used. The file is line-oriented, with the following format: <manualname> <whitespace> <keyword> <whitespace> <urlprefix> with <keyword> being "mono" or "split". Thus texinfo split http://www.gnu.org/software/texinfo/manual/texinfo/html_node/ texinfo mono http://www.gnu.org/software/texinfo/manual/texinfo/texinfo.html If the keyword is 'split', that is the target is split, the urlprefix gives the directory and host name. If the keyword is 'mono', that is the target is mono, the urlprefix gives directory, host and file name. '#' followed by a space begins comments. '#' followed by another character cannot begin comments as there are # in urls. @end ignore @node Command List @appendix @@-Command List @cindex Alphabetical @@-command list @cindex List of @@-commands @cindex @@-command list @cindex Reference to @@-commands Here is an alphabetical list of the @@-commands in Texinfo. Square brackets, @t{[}@w{ }@t{]}, indicate optional arguments; an ellipsis, @samp{@dots{}}, indicates repeated text. More specifics on the general syntax of different @@-commands are given in the section below. @menu * Command Syntax:: General syntax for varieties of @@-commands. @end menu @sp 1 @table @code @item @@@var{whitespace} An @code{@@} followed by a space, tab, or newline produces a normal, stretchable, interword space. @xref{Multiple Spaces}. @item @@! Generate an exclamation point that really does end a sentence (usually after an end-of-sentence capital letter). @xref{Ending a Sentence}. @item @@" @itemx @@' Generate an umlaut or acute accent, respectively, over the next character, as in @"o and @'o. @xref{Inserting Accents}. @item @@* Force a line break. @xref{Line Breaks}. @item @@,@{@var{c}@} Generate a cedilla accent under @var{c}, as in @,{c}. @xref{Inserting Accents}. @item @@- Insert a discretionary hyphenation point. @xref{- and hyphenation}. @item @@. Produce a period that really does end a sentence (usually after an end-of-sentence capital letter). @xref{Ending a Sentence}. @item @@/ Produces no output, but allows a line break. @xref{Line Breaks}. @item @@: Indicate to @TeX{} that an immediately preceding period, question mark, exclamation mark, or colon does not end a sentence. Prevent @TeX{} from inserting extra whitespace as it does at the end of a sentence. The command has no effect on the Info file output. @xref{Not Ending a Sentence}. @item @@= Generate a macron (bar) accent over the next character, as in @=o. @xref{Inserting Accents}. @item @@? Generate a question mark that really does end a sentence (usually after an end-of-sentence capital letter). @xref{Ending a Sentence}. @item @@@@ Stands for an at sign, @samp{@@}. @xref{Atsign Braces Comma, , Inserting @@ and @{@} and @comma{}}. @item @@\ Stands for a backslash (@samp{\}) inside @code{@@math}. @xref{math,,@code{math}}. @item @@^ @itemx @@` Generate a circumflex (hat) or grave accent, respectively, over the next character, as in @^o and @`e. @xref{Inserting Accents}. @item @@@{ Stands for a left brace, @samp{@{}. @xref{Atsign Braces Comma, , Inserting @@ and @{@} and @comma{}}. @item @@@} Stands for a right-hand brace, @samp{@}}.@* @xref{Atsign Braces Comma, , Inserting @@ and @{@} and @comma{}}. @item @@~ Generate a tilde accent over the next character, as in @~N. @xref{Inserting Accents}. @item @@AA@{@} @itemx @@aa@{@} Generate the uppercase and lowercase Scandinavian A-ring letters, respectively: @AA{}, @aa{}. @xref{Inserting Accents}. @item @@abbr@{@var{abbreviation}@} Tag @var{abbreviation} as an abbreviation, such as `Comput.'. @xref{abbr,, @code{abbr}}. @item @@acronym@{@var{acronym}@} Tag @var{acronym} as an acronym, such as `NASA'. @xref{acronym,, @code{acronym}}. @item @@AE@{@} @itemx @@ae@{@} Generate the uppercase and lowercase AE ligatures, respectively: @AE{}, @ae{}. @xref{Inserting Accents}. @itemx @@afivepaper Change page dimensions for the A5 paper size. @xref{A4 Paper}. @item @@afourlatex @itemx @@afourpaper @itemx @@afourwide Change page dimensions for the A4 paper size. @xref{A4 Paper}. @item @@alias @var{new}=@var{existing} Make the command @samp{@@@var{new}} an alias for the existing command @samp{@@@var{existing}}. @xref{alias}. @item @@anchor@{@var{name}@} Define @var{name} as the current location for use as a cross-reference target. @xref{anchor,, @code{@@anchor}}. @item @@appendix @var{title} Begin an appendix. The title appears in the table of contents of a printed manual. In Info, the title is underlined with asterisks. @xref{unnumbered & appendix, , The @code{@@unnumbered} and @code{@@appendix} Commands}.@refill @item @@appendixsec @var{title} @itemx @@appendixsection @var{title} Begin an appendix section within an appendix. The section title appears in the table of contents of a printed manual. In Info, the title is underlined with equal signs. @code{@@appendixsection} is a longer spelling of the @code{@@appendixsec} command. @xref{unnumberedsec appendixsec heading, , Section Commands}.@refill @item @@appendixsubsec @var{title} Begin an appendix subsection within an appendix. The title appears in the table of contents of a printed manual. In Info, the title is underlined with hyphens. @xref{unnumberedsubsec appendixsubsec subheading, , Subsection Commands}.@refill @item @@appendixsubsubsec @var{title} Begin an appendix subsubsection within an appendix subsection. The title appears in the table of contents of a printed manual. In Info, the title is underlined with periods. @xref{subsubsection,, The `subsub' Commands}.@refill @item @@asis Used following @code{@@table}, @code{@@ftable}, and @code{@@vtable} to print the table's first column without highlighting (``as is''). @xref{Two-column Tables, , Making a Two-column Table}.@refill @item @@author @var{author} Typeset @var{author} flushleft and underline it. @xref{title subtitle author, , The @code{@@title} and @code{@@author} Commands}.@refill @item @@b@{@var{text}@} Print @var{text} in @b{bold} font. No effect in Info. @xref{Fonts}.@refill @ignore @item @@br Force a paragraph break. If used within a line, follow @code{@@br} with braces. @xref{br, , @code{@@br}}.@refill @end ignore @item @@bullet@{@} Generate a large round dot, or the closest possible thing to one. @xref{bullet, , @code{@@bullet}}.@refill @item @@bye Stop formatting a file. The formatters do not see the contents of a file following an @code{@@bye} command. @xref{Ending a File}.@refill @item @@c @var{comment} Begin a comment in Texinfo. The rest of the line does not appear in either the Info file or the printed manual. A synonym for @code{@@comment}. @xref{Comments}. @item @@caption Define the full caption for a @code{@@float}. @xref{caption shortcaption}. @item @@cartouche Highlight an example or quotation by drawing a box with rounded corners around it. Pair with @code{@@end cartouche}. No effect in Info. @xref{cartouche, , Drawing Cartouches Around Examples}.)@refill @item @@center @var{line-of-text} Center the line of text following the command. @xref{titlefont center sp, , @code{@@center}}.@refill @item @@centerchap @var{line-of-text} Like @code{@@chapter}, but centers the chapter title. @xref{chapter,, @code{@@chapter}}. @item @@chapheading @var{title} Print a chapter-like heading in the text, but not in the table of contents of a printed manual. In Info, the title is underlined with asterisks. @xref{majorheading & chapheading, , @code{@@majorheading} and @code{@@chapheading}}.@refill @item @@chapter @var{title} Begin a chapter. The chapter title appears in the table of contents of a printed manual. In Info, the title is underlined with asterisks. @xref{chapter, , @code{@@chapter}}.@refill @item @@cindex @var{entry} Add @var{entry} to the index of concepts. @xref{Index Entries, , Defining the Entries of an Index}.@refill @item @@cite@{@var{reference}@} Highlight the name of a book or other reference that lacks a companion Info file. @xref{cite, , @code{@@cite}}.@refill @item @@clear @var{flag} Unset @var{flag}, preventing the Texinfo formatting commands from formatting text between subsequent pairs of @code{@@ifset @var{flag}} and @code{@@end ifset} commands, and preventing @code{@@value@{@var{flag}@}} from expanding to the value to which @var{flag} is set. @xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill @item @@code@{@var{sample-code}@} Highlight text that is an expression, a syntactically complete token of a program, or a program name. @xref{code, , @code{@@code}}.@refill @item @@comma@{@} Insert a comma `,' character; only needed when a literal comma would be taken as an argument separator. @xref{Inserting a Comma}. @item @@command@{@var{command-name}@} Indicate a command name, such as @command{ls}. @xref{command,, @code{@@command}}. @item @@comment @var{comment} Begin a comment in Texinfo. The rest of the line does not appear in either the Info file or the printed manual. A synonym for @code{@@c}. @xref{Comments}. @item @@contents Print a complete table of contents. Has no effect in Info, which uses menus instead. @xref{Contents, , Generating a Table of Contents}.@refill @item @@copyright@{@} Generate the copyright symbol @copyright{}. @xref{copyright symbol,, @code{@@copyright@{@}}}. @ignore @item @@ctrl@{@var{ctrl-char}@} Describe an @sc{ascii} control character. Insert actual control character into Info file. @xref{ctrl, , @code{@@ctrl}}.@refill @end ignore @item @@defcodeindex @var{index-name} Define a new index and its indexing command. Print entries in an @code{@@code} font. @xref{New Indices, , Defining New Indices}.@refill @item @@defcv @var{category} @var{class} @var{name} @itemx @@defcvx @var{category} @var{class} @var{name} Format a description for a variable associated with a class in object-oriented programming. Takes three arguments: the category of thing being defined, the class to which it belongs, and its name. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@deffn @var{category} @var{name} @var{arguments}@dots{} @itemx @@deffnx @var{category} @var{name} @var{arguments}@dots{} Format a description for a function, interactive command, or similar entity that may take arguments. @code{@@deffn} takes as arguments the category of entity being described, the name of this particular entity, and its arguments, if any. @xref{Definition Commands}.@refill @item @@defindex @var{index-name} Define a new index and its indexing command. Print entries in a roman font. @xref{New Indices, , Defining New Indices}.@refill @item @@definfoenclose @var{newcmd}, @var{before}, @var{after}, Create new @@-command @var{newcmd} for Info that marks text by enclosing it in strings that precede and follow the text. @xref{definfoenclose}. @item @@defivar @var{class} @var{instance-variable-name} @itemx @@defivarx @var{class} @var{instance-variable-name} This command formats a description for an instance variable in object-oriented programming. The command is equivalent to @samp{@@defcv @{Instance Variable@} @dots{}}. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@defmac @var{macroname} @var{arguments}@dots{} @itemx @@defmacx @var{macroname} @var{arguments}@dots{} Format a description for a macro. The command is equivalent to @samp{@@deffn Macro @dots{}}. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@defmethod @var{class} @var{method-name} @var{arguments}@dots{} @itemx @@defmethodx @var{class} @var{method-name} @var{arguments}@dots{} Format a description for a method in object-oriented programming. The command is equivalent to @samp{@@defop Method @dots{}}. Takes as arguments the name of the class of the method, the name of the method, and its arguments, if any. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@defop @var{category} @var{class} @var{name} @var{arguments}@dots{} @itemx @@defopx @var{category} @var{class} @var{name} @var{arguments}@dots{} Format a description for an operation in object-oriented programming. @code{@@defop} takes as arguments the overall name of the category of operation, the name of the class of the operation, the name of the operation, and its arguments, if any. @xref{Definition Commands}, and @ref{Abstract Objects}. @item @@defopt @var{option-name} @itemx @@defoptx @var{option-name} Format a description for a user option. The command is equivalent to @samp{@@defvr @{User Option@} @dots{}}. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@defspec @var{special-form-name} @var{arguments}@dots{} @itemx @@defspecx @var{special-form-name} @var{arguments}@dots{} Format a description for a special form. The command is equivalent to @samp{@@deffn @{Special Form@} @dots{}}. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@deftp @var{category} @var{name-of-type} @var{attributes}@dots{} @itemx @@deftpx @var{category} @var{name-of-type} @var{attributes}@dots{} Format a description for a data type. @code{@@deftp} takes as arguments the category, the name of the type (which is a word like @samp{int} or @samp{float}), and then the names of attributes of objects of that type. @xref{Definition Commands}, and @ref{Data Types}. @item @@deftypecv @var{category} @var{class} @var{data-type} @var{name} @itemx @@deftypecvx @var{category} @var{class} @var{data-type} @var{name} Format a description for a typed class variable in object-oriented programming. @xref{Definition Commands}, and @ref{Abstract Objects}. @item @@deftypefn @var{classification} @var{data-type} @var{name} @var{arguments}@dots{} @itemx @@deftypefnx @var{classification} @var{data-type} @var{name} @var{arguments}@dots{} Format a description for a function or similar entity that may take arguments and that is typed. @code{@@deftypefn} takes as arguments the classification of entity being described, the type, the name of the entity, and its arguments, if any. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@deftypefun @var{data-type} @var{function-name} @var{arguments}@dots{} @itemx @@deftypefunx @var{data-type} @var{function-name} @var{arguments}@dots{} Format a description for a function in a typed language. The command is equivalent to @samp{@@deftypefn Function @dots{}}. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@deftypeivar @var{class} @var{data-type} @var{variable-name} @itemx @@deftypeivarx @var{class} @var{data-type} @var{variable-name} Format a description for a typed instance variable in object-oriented programming. @xref{Definition Commands}, and @ref{Abstract Objects}. @item @@deftypemethod @var{class} @var{data-type} @var{method-name} @var{arguments}@dots{} @itemx @@deftypemethodx @var{class} @var{data-type} @var{method-name} @var{arguments}@dots{} Format a description for a typed method in object-oriented programming. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@deftypeop @var{category} @var{class} @var{data-type} @var{name} @var{arguments}@dots{} @itemx @@deftypeopx @var{category} @var{class} @var{data-type} @var{name} @var{arguments}@dots{} Format a description for a typed operation in object-oriented programming. @xref{Definition Commands}, and @ref{Abstract Objects}. @item @@deftypevar @var{data-type} @var{variable-name} @itemx @@deftypevarx @var{data-type} @var{variable-name} Format a description for a variable in a typed language. The command is equivalent to @samp{@@deftypevr Variable @dots{}}. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@deftypevr @var{classification} @var{data-type} @var{name} @itemx @@deftypevrx @var{classification} @var{data-type} @var{name} Format a description for something like a variable in a typed language---an entity that records a value. Takes as arguments the classification of entity being described, the type, and the name of the entity. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@defun @var{function-name} @var{arguments}@dots{} @itemx @@defunx @var{function-name} @var{arguments}@dots{} Format a description for functions. The command is equivalent to @samp{@@deffn Function @dots{}}. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@defvar @var{variable-name} @itemx @@defvarx @var{variable-name} Format a description for variables. The command is equivalent to @samp{@@defvr Variable @dots{}}. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@defvr @var{category} @var{name} @itemx @@defvrx @var{category} @var{name} Format a description for any kind of variable. @code{@@defvr} takes as arguments the category of the entity and the name of the entity. @xref{Definition Commands}, and @ref{deffnx,, Def Cmds in Detail}. @item @@detailmenu Avoid @code{makeinfo} confusion stemming from the detailed node listing in a master menu. @xref{Master Menu Parts}. @item @@dfn@{@var{term}@} Highlight the introductory or defining use of a term. @xref{dfn, , @code{@@dfn}}.@refill @item @@dircategory @var{dirpart} Specify a part of the Info directory menu where this file's entry should go. @xref{Installing Dir Entries}. @item @@direntry Begin the Info directory menu entry for this file. Pair with @code{@@end direntry}. @xref{Installing Dir Entries}. @item @@display Begin a kind of example. Like @code{@@example} (indent text, do not fill), but do not select a new font. Pair with @code{@@end display}. @xref{display, , @code{@@display}}. @item @@dmn@{@var{dimension}@} Format a unit of measure, as in 12@dmn{pt}. Causes @TeX{} to insert a thin space before @var{dimension}. No effect in Info. @xref{dmn, , @code{@@dmn}}. @item @@docbook Enter Docbook completely. Pair with @code{@@end docbook}. @xref{Raw Formatter Commands}. @item @@documentdescription Set the document description text, included in the HTML output. Pair with @code{@@end documentdescription}. @xref{documentdescription,, @code{@@documentdescription}}. @item @@documentencoding @var{enc} Declare the input encoding to be @var{enc}. @xref{documentencoding,, @code{@@documentencoding}}. @item @@documentlanguage @var{CC} Declare the document language as the two-character ISO-639 abbreviation @var{CC}. @xref{documentlanguage,, @code{@@documentlanguage}}. @item @@dotaccent@{@var{c}@} Generate a dot accent over the character @var{c}, as in @dotaccent{o}. @xref{Inserting Accents}. @item @@dots@{@} Insert an ellipsis: @samp{@dots{}}. @xref{dots, , @code{@@dots}}.@refill @item @@email@{@var{address}[, @var{displayed-text}]@} Indicate an electronic mail address. @xref{email, , @code{@@email}}. @item @@emph@{@var{text}@} Highlight @var{text}; text is displayed in @emph{italics} in printed output, and surrounded by asterisks in Info. @xref{Emphasis, , Emphasizing Text}. @item @@end @var{environment} Ends @var{environment}, as in @samp{@@end example}. @xref{Formatting Commands,,@@-commands}. @item @@env@{@var{environment-variable}@} Indicate an environment variable name, such as @env{PATH}. @xref{env,, @code{@@env}}. @item @@enddots@{@} Generate an end-of-sentence of ellipsis, like this @enddots{} @xref{dots,,@code{@@dots@{@}}}. @item @@enumerate [@var{number-or-letter}] Begin a numbered list, using @code{@@item} for each entry. Optionally, start list with @var{number-or-letter}. Pair with @code{@@end enumerate}. @xref{enumerate, , @code{@@enumerate}}.@refill @item @@equiv@{@} Indicate to the reader the exact equivalence of two forms with a glyph: @samp{@equiv{}}. @xref{Equivalence}.@refill @item @@euro@{@} Generate the Euro currency sign. @xref{euro,,@code{@@euro@{@}}}. @item @@error@{@} Indicate to the reader with a glyph that the following text is an error message: @samp{@error{}}. @xref{Error Glyph}.@refill @item @@evenfooting [@var{left}] @@| [@var{center}] @@| [@var{right}] @itemx @@evenheading [@var{left}] @@| [@var{center}] @@| [@var{right}] Specify page footings resp.@: headings for even-numbered (left-hand) pages. @xref{Custom Headings, , How to Make Your Own Headings}.@refill @item @@everyfooting [@var{left}] @@| [@var{center}] @@| [@var{right}] @itemx @@everyheading [@var{left}] @@| [@var{center}] @@| [@var{right}] Specify page footings resp.@: headings for every page. Not relevant to Info. @xref{Custom Headings, , How to Make Your Own Headings}.@refill @item @@example Begin an example. Indent text, do not fill, and select fixed-width font. Pair with @code{@@end example}. @xref{example, , @code{@@example}}.@refill @item @@exampleindent @var{indent} Indent example-like environments by @var{indent} number of spaces (perhaps 0). @xref{exampleindent,, Paragraph Indenting}. @item @@exclamdown@{@} Produce an upside-down exclamation point. @xref{Inserting Accents}. @item @@exdent @var{line-of-text} Remove any indentation a line might have. @xref{exdent, , Undoing the Indentation of a Line}.@refill @item @@expansion@{@} Indicate the result of a macro expansion to the reader with a special glyph: @samp{@expansion{}}. @xref{expansion, , @expansion{} Indicating an Expansion}.@refill @item @@file@{@var{filename}@} Highlight the name of a file, buffer, node, or directory. @xref{file, , @code{@@file}}.@refill @item @@finalout Prevent @TeX{} from printing large black warning rectangles beside over-wide lines. @xref{Overfull hboxes}.@refill @item @@findex @var{entry} Add @var{entry} to the index of functions. @xref{Index Entries, , Defining the Entries of an Index}.@refill @item @@float Environment to define floating material. Pair with @code{@@end float}. @xref{Floats}. @item @@flushleft @itemx @@flushright Left justify every line but leave the right end ragged. Leave font as is. Pair with @code{@@end flushleft}. @code{@@flushright} analogous. @xref{flushleft & flushright, , @code{@@flushleft} and @code{@@flushright}}.@refill @item @@footnote@{@var{text-of-footnote}@} Enter a footnote. Footnote text is printed at the bottom of the page by @TeX{}; Info may format in either `End' node or `Separate' node style. @xref{Footnotes}.@refill @item @@footnotestyle @var{style} Specify an Info file's footnote style, either @samp{end} for the end node style or @samp{separate} for the separate node style. @xref{Footnotes}.@refill @item @@format Begin a kind of example. Like @code{@@display}, but do not narrow the margins. Pair with @code{@@end format}. @xref{example,, @code{@@example}}. @item @@ftable @var{formatting-command} Begin a two-column table, using @code{@@item} for each entry. Automatically enter each of the items in the first column into the index of functions. Pair with @code{@@end ftable}. The same as @code{@@table}, except for indexing. @xref{ftable vtable, , @code{@@ftable} and @code{@@vtable}}.@refill @item @@group Hold text together that must appear on one printed page. Pair with @code{@@end group}. Not relevant to Info. @xref{group, , @code{@@group}}.@refill @item @@H@{@var{c}@} Generate the long Hungarian umlaut accent over @var{c}, as in @H{o}. @item @@heading @var{title} Print an unnumbered section-like heading in the text, but not in the table of contents of a printed manual. In Info, the title is underlined with equal signs. @xref{unnumberedsec appendixsec heading, , Section Commands}.@refill @item @@headings @var{on-off-single-double} Turn page headings on or off, and/or specify single-sided or double-sided page headings for printing. @xref{headings on off, , The @code{@@headings} Command}. @item @@html Enter HTML completely. Pair with @code{@@end html}. @xref{Raw Formatter Commands}. @item @@hyphenation@{@var{hy-phen-a-ted words}@} Explicitly define hyphenation points. @xref{- and hyphenation,, @code{@@-} and @code{@@hyphenation}}. @item @@i@{@var{text}@} Print @var{text} in @i{italic} font. No effect in Info. @xref{Fonts}. @item @@ifclear @var{flag} If @var{flag} is cleared, the Texinfo formatting commands format text between @code{@@ifclear @var{flag}} and the following @code{@@end ifclear} command. @xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill @item @@ifdocbook @itemx @@ifhtml @itemx @@ifinfo Begin text that will appear only in the given output format. @code{@@ifinfo} output appears in both Info and (for historical compatibility) plain text output. Pair with @code{@@end ifdocbook} resp.@: @code{@@end ifhtml} resp.@: @code{@@end ifinfo}. @xref{Conditionals}. @item @@ifnotdocbook @itemx @@ifnothtml @itemx @@ifnotinfo @itemx @@ifnotplaintext @itemx @@ifnottex @itemx @@ifnotxml Begin a stretch of text that will be ignored in one output format but not the others. The text appears in the formats not specified: @code{@@ifnothtml} text is omitted from html output, etc. The exception is @code{@@ifnotinfo} text, which is omitted from plain text output as well as Info output. Pair with the corresponding @code{@@end ifnot@var{format}}. @xref{Conditionals}. @item @@ifplaintext Begin text that will appear only in the plain text output. Pair with @code{@@end ifplaintext}. @xref{Conditionals}. @item @@ifset @var{flag} If @var{flag} is set, the Texinfo formatting commands format text between @code{@@ifset @var{flag}} and the following @code{@@end ifset} command. @xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill @item @@iftex Begin text that will not appear in the Info file or other output, but will be processed only by @TeX{}. Pair with @code{@@end iftex}. @xref{Conditionals, , Conditionally Visible Text}.@refill @item @@ifxml Begin text that will appear only in the XML output. Pair with @code{@@end ifxml}. @xref{Conditionals}. @item @@ignore Begin text that will not appear in any output. Pair with @code{@@end ignore}. @xref{Comments, , Comments and Ignored Text}. @item @@image@{@var{filename}, [@var{width}], [@var{height}], [@var{alt}], [@var{ext}]@} Include graphics image in external @var{filename} scaled to the given @var{width} and/or @var{height}, using @var{alt} text and looking for @samp{@var{filename}.@var{ext}} in HTML. @xref{Images}. @item @@include @var{filename} Incorporate the contents of the file @var{filename} into the Info file or printed document. @xref{Include Files}.@refill @item @@indicateurl@{@var{indicateurl}@} Indicate text that is a uniform resource locator for the World Wide Web. @xref{indicateurl, , @code{@@indicateurl}}. @item @@inforef@{@var{node-name}, [@var{entry-name}], @var{info-file-name}@} Make a cross reference to an Info file for which there is no printed manual. @xref{inforef, , Cross references using @code{@@inforef}}.@refill @item \input @var{macro-definitions-file} Use the specified macro definitions file. This command is used only in the first line of a Texinfo file to cause @TeX{} to make use of the @file{texinfo} macro definitions file. The backslash in @code{\input} is used instead of an @code{@@} because @TeX{} does not recognize @code{@@} until after it has read the definitions file. @xref{Texinfo File Header}. @item @@item Indicate the beginning of a marked paragraph for @code{@@itemize} and @code{@@enumerate}; indicate the beginning of the text of a first column entry for @code{@@table}, @code{@@ftable}, and @code{@@vtable}. @xref{Lists and Tables}.@refill @item @@itemize @var{mark-generating-character-or-command} Produce a sequence of indented paragraphs, with a mark inside the left margin at the beginning of each paragraph. Pair with @code{@@end itemize}. @xref{itemize, , @code{@@itemize}}.@refill @item @@itemx Like @code{@@item} but do not generate extra vertical space above the item text. @xref{itemx, , @code{@@itemx}}.@refill @item @@kbd@{@var{keyboard-characters}@} Indicate text that is characters of input to be typed by users. @xref{kbd, , @code{@@kbd}}.@refill @item @@kbdinputstyle @var{style} Specify when @code{@@kbd} should use a font distinct from @code{@@code}. @xref{kbd, , @code{@@kbd}}.@refill @item @@key@{@var{key-name}@} Indicate a name for a key on a keyboard. @xref{key, , @code{@@key}}.@refill @item @@kindex @var{entry} Add @var{entry} to the index of keys. @xref{Index Entries, , Defining the Entries of an Index}.@refill @item @@L@{@} @itemx @@l@{@} Generate the uppercase and lowercase Polish suppressed-L letters, respectively: @L{}, @l{}. @item @@LaTeX@{@} Insert the logo @LaTeX{}. @xref{tex, , @TeX{} and @LaTeX{}}. @item @@lisp Begin an example of Lisp code. Indent text, do not fill, and select fixed-width font. Pair with @code{@@end lisp}. @xref{lisp, , @code{@@lisp}}. @item @@listoffloats Produce a table-of-contents-like listing of @code{@@float}s. @xref{listoffloats}. @item @@lowersections Change subsequent chapters to sections, sections to subsections, and so on. @xref{Raise/lower sections, , @code{@@raisesections} and @code{@@lowersections}}.@refill @item @@macro @var{macroname} @{@var{params}@} Define a new Texinfo command @code{@@@var{macroname}@{@var{params}@}}. Only supported by @code{makeinfo} and @code{texi2dvi}. @xref{Defining Macros}. @item @@majorheading @var{title} Print a chapter-like heading in the text, but not in the table of contents of a printed manual. Generate more vertical whitespace before the heading than the @code{@@chapheading} command. @xref{majorheading & chapheading, , @code{@@majorheading} and @code{@@chapheading}}.@refill @item @@math@{@var{mathematical-expression}@} Format a mathematical expression. @xref{math, , @code{@@math}: Inserting Mathematical Expressions}. @item @@menu Mark the beginning of a menu of nodes in Info. No effect in a printed manual. Pair with @code{@@end menu}. @xref{Menus}.@refill @item @@minus@{@} Generate a minus sign, `@minus{}'. @xref{minus, , @code{@@minus}}.@refill @item @@multitable @var{column-width-spec} Begin a multi-column table. Pair with @code{@@end multitable}. @xref{Multitable Column Widths}. @item @@need @var{n} Start a new page in a printed manual if fewer than @var{n} mils (thousandths of an inch) remain on the current page. @xref{need, , @code{@@need}}.@refill @item @@node @var{name}, @var{next}, @var{previous}, @var{up} Define the beginning of a new node in Info, and serve as a locator for references for @TeX{}. @xref{node, , @code{@@node}}.@refill @item @@noindent Prevent text from being indented as if it were a new paragraph. @xref{noindent, , @code{@@noindent}}.@refill @item @@novalidate Suppress validation of node references, omit creation of auxiliary files with @TeX{}. Use before @code{@@setfilename}. @xref{Pointer Validation}. @item @@O@{@} @itemx @@o@{@} Generate the uppercase and lowercase O-with-slash letters, respectively: @O{}, @o{}. @item @@oddfooting [@var{left}] @@| [@var{center}] @@| [@var{right}] @itemx @@oddheading [@var{left}] @@| [@var{center}] @@| [@var{right}] Specify page footings resp.@: headings for odd-numbered (right-hand) pages. @xref{Custom Headings, , How to Make Your Own Headings}.@refill @item @@OE@{@} @itemx @@oe@{@} Generate the uppercase and lowercase OE ligatures, respectively: @OE{}, @oe{}. @xref{Inserting Accents}. @item @@option@{@var{option-name}@} Indicate a command-line option, such as @option{-l} or @option{--help}. @xref{option,, @code{@@option}}. @item @@page Start a new page in a printed manual. No effect in Info. @xref{page, , @code{@@page}}.@refill @item @@pagesizes [@var{width}][, @var{height}] Change page dimensions. @xref{pagesizes}. @item @@paragraphindent @var{indent} Indent paragraphs by @var{indent} number of spaces (perhaps 0); preserve source file indentation if @var{indent} is @code{asis}. @xref{paragraphindent,, Paragraph Indenting}. @item @@pindex @var{entry} Add @var{entry} to the index of programs. @xref{Index Entries, , Defining the Entries of an Index}.@refill @item @@point@{@} Indicate the position of point in a buffer to the reader with a glyph: @samp{@point{}}. @xref{Point Glyph, , Indicating Point in a Buffer}.@refill @item @@pounds@{@} Generate the pounds sterling currency sign. @xref{pounds,,@code{@@pounds@{@}}}. @item @@print@{@} Indicate printed output to the reader with a glyph: @samp{@print{}}. @xref{Print Glyph}.@refill @item @@printindex @var{index-name} Print an alphabetized two-column index in a printed manual or generate an alphabetized menu of index entries for Info. @xref{Printing Indices & Menus}.@refill @item @@pxref@{@var{node-name}, [@var{entry}], [@var{topic-or-title}], [@var{info-file}], [@var{manual}]@} Make a reference that starts with a lower case `see' in a printed manual. Use within parentheses only. Do not follow command with a punctuation mark---the Info formatting commands automatically insert terminating punctuation as needed. Only the first argument is mandatory. @xref{pxref, , @code{@@pxref}}.@refill @item @@questiondown@{@} Generate an upside-down question mark. @xref{Inserting Accents}. @item @@quotation Narrow the margins to indicate text that is quoted from another real or imaginary work. Takes optional argument of prefix text. Pair with @code{@@end quotation}. @xref{quotation, , @code{@@quotation}}.@refill @item @@r@{@var{text}@} Print @var{text} in @r{roman} font. No effect in Info. @xref{Fonts}.@refill @item @@raisesections Change subsequent sections to chapters, subsections to sections, and so on. @xref{Raise/lower sections, , @code{@@raisesections} and @code{@@lowersections}}.@refill @item @@ref@{@var{node-name}, [@var{entry}], [@var{topic-or-title}], [@var{info-file}], [@var{manual}]@} Make a reference. In a printed manual, the reference does not start with a `See'. Follow command with a punctuation mark. Only the first argument is mandatory. @xref{ref, , @code{@@ref}}.@refill @item @@refill This command used to refill and indent the paragraph after all the other processing has been done. It is no longer needed, since all formatters now automatically refill as needed, but you may still see it in the source to some manuals, as it does no harm. @item @@registeredsymbol@{@} Generate the legal symbol @registeredsymbol{}. @xref{registered symbol,, @code{@@registeredsymbol@{@}}}. @item @@result@{@} Indicate the result of an expression to the reader with a special glyph: @samp{@result{}}. @xref{result, , @code{@@result}}.@refill @item @@ringaccent@{@var{c}@} Generate a ring accent over the next character, as in @ringaccent{o}. @xref{Inserting Accents}. @item @@samp@{@var{text}@} Highlight @var{text} that is a literal example of a sequence of characters. Used for single characters, for statements, and often for entire shell commands. @xref{samp, , @code{@@samp}}.@refill @item @@sansserif@{@var{text}@} Print @var{text} in a @sansserif{sans serif} font if possible. No effect in Info. @xref{Fonts}. @item @@sc@{@var{text}@} Set @var{text} in a printed output in @sc{the small caps font} and set text in the Info file in uppercase letters. @xref{Smallcaps}.@refill @item @@section @var{title} Begin a section within a chapter. In a printed manual, the section title is numbered and appears in the table of contents. In Info, the title is underlined with equal signs. @xref{section, , @code{@@section}}.@refill @item @@set @var{flag} [@var{string}] Make @var{flag} active, causing the Texinfo formatting commands to format text between subsequent pairs of @code{@@ifset @var{flag}} and @code{@@end ifset} commands. Optionally, set value of @var{flag} to @var{string}. @xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}. @item @@setchapternewpage @var{on-off-odd} Specify whether chapters start on new pages, and if so, whether on odd-numbered (right-hand) new pages. @xref{setchapternewpage, , @code{@@setchapternewpage}}. @item @@setcontentsaftertitlepage Put the table of contents after the @samp{@@end titlepage} even if the @code{@@contents} command is not there. @xref{Contents}. @item @@setfilename @var{info-file-name} Provide a name to be used by the Info file. This command is essential for @TeX{} formatting as well, even though it produces no output. @xref{setfilename, , @code{@@setfilename}}. @item @@setshortcontentsaftertitlepage Place the short table of contents after the @samp{@@end titlepage} command even if the @code{@@shortcontents} command is not there. @xref{Contents}. @item @@settitle @var{title} Provide a title for page headers in a printed manual, and the default document description for HTML @samp{<head>}. @xref{settitle, , @code{@@settitle}}.@refill @item @@shortcaption Define the short caption for a @code{@@float}. @xref{caption shortcaption}. @item @@shortcontents Print a short table of contents. Not relevant to Info, which uses menus rather than tables of contents. A synonym for @code{@@summarycontents}. @xref{Contents, , Generating a Table of Contents}.@refill @item @@shorttitlepage @var{title} Generate a minimal title page. @xref{titlepage,,@code{@@titlepage}}. @item @@slanted@{@var{text}@} Print @var{text} in a @slanted{slanted} font if possible. No effect in Info. @xref{Fonts}. @item @@smallbook Cause @TeX{} to produce a printed manual in a 7 by 9.25 inch format rather than the regular 8.5 by 11 inch format. @xref{smallbook, , Printing Small Books}. Also, see @ref{small}. @item @@smalldisplay Begin a kind of example. Like @code{@@smallexample} (narrow margins, no filling), but do not select the fixed-width font. Pair with @code{@@end smalldisplay}. @xref{small}. @item @@smallexample Indent text to indicate an example. Do not fill, select fixed-width font, narrow the margins. In printed manuals, print text in a smaller font than with @code{@@example}. Pair with @code{@@end smallexample}. @xref{small}. @item @@smallformat Begin a kind of example. Like @code{@@smalldisplay}, but do not narrow the margins. Pair with @code{@@end smallformat}. @xref{small}. @item @@smalllisp Begin an example of Lisp code. Same as @code{@@smallexample}. Pair with @code{@@end smalllisp}. @xref{small}. @item @@sp @var{n} Skip @var{n} blank lines. @xref{sp, , @code{@@sp}}.@refill @item @@ss@{@} Generate the German sharp-S es-zet letter, @ss{}. @xref{Inserting Accents}. @item @@strong @{@var{text}@} Emphasize @var{text} by typesetting it in a @strong{bold} font for the printed manual and by surrounding it with asterisks for Info. @xref{emph & strong, , Emphasizing Text}.@refill @item @@subheading @var{title} Print an unnumbered subsection-like heading in the text, but not in the table of contents of a printed manual. In Info, the title is underlined with hyphens. @xref{unnumberedsubsec appendixsubsec subheading, , @code{@@unnumberedsubsec} @code{@@appendixsubsec} @code{@@subheading}}.@refill @item @@subsection @var{title} Begin a subsection within a section. In a printed manual, the subsection title is numbered and appears in the table of contents. In Info, the title is underlined with hyphens. @xref{subsection, , @code{@@subsection}}.@refill @item @@subsubheading @var{title} Print an unnumbered subsubsection-like heading in the text, but not in the table of contents of a printed manual. In Info, the title is underlined with periods. @xref{subsubsection, , The `subsub' Commands}.@refill @item @@subsubsection @var{title} Begin a subsubsection within a subsection. In a printed manual, the subsubsection title is numbered and appears in the table of contents. In Info, the title is underlined with periods. @xref{subsubsection, , The `subsub' Commands}.@refill @item @@subtitle @var{title} In a printed manual, set a subtitle in a normal sized font flush to the right-hand side of the page. Not relevant to Info, which does not have title pages. @xref{title subtitle author, , @code{@@title} @code{@@subtitle} and @code{@@author} Commands}.@refill @item @@summarycontents Print a short table of contents. Not relevant to Info, which uses menus rather than tables of contents. A synonym for @code{@@shortcontents}. @xref{Contents, , Generating a Table of Contents}.@refill @item @@syncodeindex @var{from-index} @var{into-index} Merge the index named in the first argument into the index named in the second argument, printing the entries from the first index in @code{@@code} font. @xref{Combining Indices}.@refill @item @@synindex @var{from-index} @var{into-index} Merge the index named in the first argument into the index named in the second argument. Do not change the font of @var{from-index} entries. @xref{Combining Indices}.@refill @item @@t@{@var{text}@} Print @var{text} in a @t{fixed-width}, typewriter-like font. No effect in Info. @xref{Fonts}.@refill @item @@tab Separate columns in a multitable. @xref{Multitable Rows}. @item @@table @var{formatting-command} Begin a two-column table, using @code{@@item} for each entry. Write each first column entry on the same line as @code{@@item}. First column entries are printed in the font resulting from @var{formatting-command}. Pair with @code{@@end table}. @xref{Two-column Tables, , Making a Two-column Table}. Also see @ref{ftable vtable, , @code{@@ftable} and @code{@@vtable}}, and @ref{itemx, , @code{@@itemx}}.@refill @item @@TeX@{@} Insert the logo @TeX{}. @xref{tex, , @TeX{} and @LaTeX{}}. @item @@tex Enter @TeX{} completely. Pair with @code{@@end tex}. @xref{Raw Formatter Commands}. @item @@thischapter @itemx @@thischaptername @itemx @@thisfile @itemx @@thispage @itemx @@thistitle Only allowed in a heading or footing. Stands for the number and name of the current chapter (in the format `Chapter 1: Title'), the chapter name only, the filename, the current page number, and the title of the document, respectively. @xref{Custom Headings, , How to Make Your Own Headings}.@refill @item @@tie@{@} Generate a normal interword space at which a line break is not allowed. @xref{tie,, @code{@@tie@{@}}}. @item @@tieaccent@{@var{cc}@} Generate a tie-after accent over the next two characters @var{cc}, as in `@tieaccent{oo}'. @xref{Inserting Accents}. @item @@tindex @var{entry} Add @var{entry} to the index of data types. @xref{Index Entries, , Defining the Entries of an Index}.@refill @item @@title @var{title} In a printed manual, set a title flush to the left-hand side of the page in a larger than normal font and underline it with a black rule. Not relevant to Info, which does not have title pages. @xref{title subtitle author, , The @code{@@title} @code{@@subtitle} and @code{@@author} Commands}.@refill @item @@titlefont@{@var{text}@} In a printed manual, print @var{text} in a larger than normal font. Not relevant to Info, which does not have title pages. @xref{titlefont center sp, , The @code{@@titlefont} @code{@@center} and @code{@@sp} Commands}.@refill @item @@titlepage Indicate to Texinfo the beginning of the title page. Write command on a line of its own. Pair with @code{@@end titlepage}. Nothing between @code{@@titlepage} and @code{@@end titlepage} appears in Info. @xref{titlepage, , @code{@@titlepage}}.@refill @item @@today@{@} Insert the current date, in `1 Jan 1900' style. @xref{Custom Headings, , How to Make Your Own Headings}.@refill @item @@top @var{title} In a Texinfo file to be formatted with @code{makeinfo}, identify the topmost @code{@@node} in the file, which must be written on the line immediately preceding the @code{@@top} command. Used for @code{makeinfo}'s node pointer insertion feature. The title is underlined with asterisks. Both the @code{@@node} line and the @code{@@top} line normally should be enclosed by @code{@@ifnottex} and @code{@@end ifnottex}. In @TeX{} and @code{texinfo-format-buffer}, the @code{@@top} command is merely a synonym for @code{@@unnumbered}. @xref{makeinfo Pointer Creation, , Creating Pointers with @code{makeinfo}}. @item @@u@{@var{c}@} @itemx @@ubaraccent@{@var{c}@} @itemx @@udotaccent@{@var{c}@} Generate a breve, underbar, or underdot accent, respectively, over or under the character @var{c}, as in @u{o}, @ubaraccent{o}, @udotaccent{o}. @xref{Inserting Accents}. @item @@unnumbered @var{title} In a printed manual, begin a chapter that appears without chapter numbers of any kind. The title appears in the table of contents of a printed manual. In Info, the title is underlined with asterisks. @xref{unnumbered & appendix, , @code{@@unnumbered} and @code{@@appendix}}.@refill @item @@unnumberedsec @var{title} In a printed manual, begin a section that appears without section numbers of any kind. The title appears in the table of contents of a printed manual. In Info, the title is underlined with equal signs. @xref{unnumberedsec appendixsec heading, , Section Commands}.@refill @item @@unnumberedsubsec @var{title} In a printed manual, begin an unnumbered subsection within a chapter. The title appears in the table of contents of a printed manual. In Info, the title is underlined with hyphens. @xref{unnumberedsubsec appendixsubsec subheading, , @code{@@unnumberedsubsec} @code{@@appendixsubsec} @code{@@subheading}}.@refill @item @@unnumberedsubsubsec @var{title} In a printed manual, begin an unnumbered subsubsection within a chapter. The title appears in the table of contents of a printed manual. In Info, the title is underlined with periods. @xref{subsubsection, , The `subsub' Commands}.@refill @item @@uref@{@var{url}[, @var{displayed-text}][, @var{replacement}@} @itemx @@url@{@var{url}[, @var{displayed-text}][, @var{replacement}@} Define a cross reference to an external uniform resource locator for the World Wide Web. @xref{uref, , @code{@@uref}}. @item @@v@{@var{c}@} Generate check accent over the character @var{c}, as in @v{o}. @xref{Inserting Accents}. @item @@value@{@var{flag}@} Replace @var{flag} with the value to which it is set by @code{@@set @var{flag}}. @xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill @item @@var@{@var{metasyntactic-variable}@} Highlight a metasyntactic variable, which is something that stands for another piece of text. @xref{var, , Indicating Metasyntactic Variables}.@refill @item @@verb@{@var{delim} @var{literal} @var{delim}@} Output @var{literal}, delimited by the single character @var{delim}, exactly as is (in the fixed-width font), including any whitespace or Texinfo special characters. @xref{verb,,@code{verb}}. @item @@verbatim Output the text of the environment exactly as is (in the fixed-width font). Pair with @code{@@end verbatim}. @xref{verbatim,,@code{verbatim}}. @item @@verbatiminclude @var{filename} Output the contents of @var{filename} exactly as is (in the fixed-width font). @xref{verbatiminclude,,@code{verbatiminclude}}. @item @@vindex @var{entry} Add @var{entry} to the index of variables. @xref{Index Entries, , Defining the Entries of an Index}.@refill @item @@vskip @var{amount} In a printed manual, insert whitespace so as to push text on the remainder of the page towards the bottom of the page. Used in formatting the copyright page with the argument @samp{0pt plus 1filll}. (Note spelling of @samp{filll}.) @code{@@vskip} may be used only in contexts ignored for Info. @xref{Copyright}. @item @@vtable @var{formatting-command} Begin a two-column table, using @code{@@item} for each entry. Automatically enter each of the items in the first column into the index of variables. Pair with @code{@@end vtable}. The same as @code{@@table}, except for indexing. @xref{ftable vtable, , @code{@@ftable} and @code{@@vtable}}.@refill @item @@w@{@var{text}@} Prevent @var{text} from being split across two lines. @xref{w, , @code{@@w}}.@refill @item @@xml Enter XML completely. Pair with @code{@@end xml}. @xref{Raw Formatter Commands}. @item @@xref@{@var{node-name}, [@var{entry}], [@var{topic-or-title}], [@var{info-file}], [@var{manual}]@} Make a reference that starts with `See' in a printed manual. Follow command with a punctuation mark. Only the first argument is mandatory. @xref{xref, , @code{@@xref}}.@refill @end table @node Command Syntax @section @@-Command Syntax @cindex @@-command syntax @cindex Syntax, of @@-commands @cindex Command syntax The character @samp{@@} is used to start special Texinfo commands. (It has the same meaning that @samp{\} has in plain @TeX{}.) Texinfo has four types of @@-command:@refill @table @asis @item 1. Non-alphabetic commands. These commands consist of an @@ followed by a punctuation mark or other character that is not part of the alphabet. Non-alphabetic commands are almost always part of the text within a paragraph, and never take any argument. The two characters (@@ and the other one) are complete in themselves; none is followed by braces. The non-alphabetic commands are: @code{@@.}, @code{@@:}, @code{@@*}, @code{@@@kbd{SPACE}}, @code{@@@kbd{TAB}}, @code{@@@kbd{NL}}, @code{@@@@}, @code{@@@{}, and @code{@@@}}.@refill @item 2. Alphabetic commands that do not require arguments. These commands start with @@ followed by a word followed by left- and right-hand braces. These commands insert special symbols in the document; they do not require arguments. For example, @code{@@dots@{@}} @result{} @samp{@dots{}}, @code{@@equiv@{@}} @result{} @samp{@equiv{}}, @code{@@TeX@{@}} @result{} `@TeX{}', and @code{@@bullet@{@}} @result{} @samp{@bullet{}}.@refill @item 3. Alphabetic commands that require arguments within braces. These commands start with @@ followed by a letter or a word, followed by an argument within braces. For example, the command @code{@@dfn} indicates the introductory or defining use of a term; it is used as follows: @samp{In Texinfo, @@@@-commands are @@dfn@{mark-up@} commands.}@refill @item 4. Alphabetic commands that occupy an entire line. These commands occupy an entire line. The line starts with @@, followed by the name of the command (a word); for example, @code{@@center} or @code{@@cindex}. If no argument is needed, the word is followed by the end of the line. If there is an argument, it is separated from the command name by a space. Braces are not used.@refill @end table @cindex Braces and argument syntax Thus, the alphabetic commands fall into classes that have different argument syntaxes. You cannot tell to which class a command belongs by the appearance of its name, but you can tell by the command's meaning: if the command stands for a glyph, it is in class 2 and does not require an argument; if it makes sense to use the command together with other text as part of a paragraph, the command is in class 3 and must be followed by an argument in braces; otherwise, it is in class 4 and uses the rest of the line as its argument.@refill The purpose of having a different syntax for commands of classes 3 and 4 is to make Texinfo files easier to read, and also to help the GNU Emacs paragraph and filling commands work properly. There is only one exception to this rule: the command @code{@@refill}, which is always used at the end of a paragraph immediately following the final period or other punctuation character. @code{@@refill} takes no argument and does @emph{not} require braces. @code{@@refill} never confuses the Emacs paragraph commands because it cannot appear at the beginning of a line. It is also no longer needed, since all formatters now refill paragraphs automatically. @node Tips @appendix Tips and Hints Here are some tips for writing Texinfo documentation:@refill @cindex Tips @cindex Usage tips @cindex Hints @itemize @bullet @item Write in the present tense, not in the past or the future. @item Write actively! For example, write ``We recommend that @dots{}'' rather than ``It is recommended that @dots{}''. @item Use 70 or 72 as your fill column. Longer lines are hard to read. @item Include a copyright notice and copying permissions. @end itemize @subsubheading Index, Index, Index! Write many index entries, in different ways. Readers like indices; they are helpful and convenient. Although it is easiest to write index entries as you write the body of the text, some people prefer to write entries afterwards. In either case, write an entry before the paragraph to which it applies. This way, an index entry points to the first page of a paragraph that is split across pages. Here are more hints we have found valuable: @itemize @bullet @item Write each index entry differently, so each entry refers to a different place in the document. @item Write index entries only where a topic is discussed significantly. For example, it is not useful to index ``debugging information'' in a chapter on reporting bugs. Someone who wants to know about debugging information will certainly not find it in that chapter. @item Consistently capitalize the first word of every concept index entry, or else consistently use lower case. Terse entries often call for lower case; longer entries for capitalization. Whichever case convention you use, please use one or the other consistently! Mixing the two styles looks bad. @item Always capitalize or use upper case for those words in an index for which this is proper, such as names of countries or acronyms. Always use the appropriate case for case-sensitive names, such as those in C or Lisp. @item Write the indexing commands that refer to a whole section immediately after the section command, and write the indexing commands that refer to a paragraph before that paragraph. In the example that follows, a blank line comes after the index entry for ``Leaping'': @example @group @@section The Dog and the Fox @@cindex Jumping, in general @@cindex Leaping @@cindex Dog, lazy, jumped over @@cindex Lazy dog jumped over @@cindex Fox, jumps over dog @@cindex Quick fox jumps over dog The quick brown fox jumps over the lazy dog. @end group @end example @noindent (Note that the example shows entries for the same concept that are written in different ways---@samp{Lazy dog}, and @samp{Dog, lazy}---so readers can look up the concept in different ways.) @end itemize @subsubheading Blank Lines @itemize @bullet @item Insert a blank line between a sectioning command and the first following sentence or paragraph, or between the indexing commands associated with the sectioning command and the first following sentence or paragraph, as shown in the tip on indexing. Otherwise, a formatter may fold title and paragraph together. @item Always insert a blank line before an @code{@@table} command and after an @code{@@end table} command; but never insert a blank line after an @code{@@table} command or before an @code{@@end table} command. @need 1000 For example, @example @group Types of fox: @@table @@samp @@item Quick Jump over lazy dogs. @end group @group @@item Brown Also jump over lazy dogs. @@end table @end group @group @@noindent On the other hand, @dots{} @end group @end example Insert blank lines before and after @code{@@itemize} @dots{} @code{@@end itemize} and @code{@@enumerate} @dots{} @code{@@end enumerate} in the same way. @end itemize @subsubheading Complete Phrases Complete phrases are easier to read than @dots{} @itemize @bullet @item Write entries in an itemized list as complete sentences; or at least, as complete phrases. Incomplete expressions @dots{} awkward @dots{} like this. @item Write the prefatory sentence or phrase for a multi-item list or table as a complete expression. Do not write ``You can set:''; instead, write ``You can set these variables:''. The former expression sounds cut off. @end itemize @subsubheading Editions, Dates and Versions Include edition numbers, version numbers, and dates in the @code{@@copying} text (for people reading the Texinfo file, and for the legal copyright in the output files). Then use @code{@@insertcopying} in the @code{@@titlepage} section (for people reading the printed output) and the Top node (for people reading the online output). It is easiest to do this using @code{@@set} and @code{@@value}. @xref{value Example, , @code{@@value} Example}, and @ref{GNU Sample Texts}. @subsubheading Definition Commands Definition commands are @code{@@deffn}, @code{@@defun}, @code{@@defmac}, and the like, and enable you to write descriptions in a uniform format.@refill @itemize @bullet @item Write just one definition command for each entity you define with a definition command. The automatic indexing feature creates an index entry that leads the reader to the definition. @item Use @code{@@table} @dots{} @code{@@end table} in an appendix that contains a summary of functions, not @code{@@deffn} or other definition commands. @end itemize @subsubheading Capitalization @itemize @bullet @item Capitalize ``Texinfo''; it is a name. Do not write the @samp{x} or @samp{i} in upper case. @item Capitalize ``Info''; it is a name. @item Write @TeX{} using the @code{@@TeX@{@}} command. Note the uppercase @samp{T} and @samp{X}. This command causes the formatters to typeset the name according to the wishes of Donald Knuth, who wrote @TeX{}. @end itemize @subsubheading Spaces Do not use spaces to format a Texinfo file, except inside of @code{@@example} @dots{} @code{@@end example} and other literal environments and commands. @need 700 For example, @TeX{} fills the following: @example @group @@kbd@{C-x v@} @@kbd@{M-x vc-next-action@} Perform the next logical operation on the version-controlled file corresponding to the current buffer. @end group @end example @need 950 @noindent so it looks like this: @iftex @quotation @kbd{C-x v} @kbd{M-x vc-next-action} Perform the next logical operation on the version-controlled file corresponding to the current buffer. @end quotation @end iftex @ifnottex @quotation `C-x v' `M-x vc-next-action' Perform the next logical operation on the version-controlled file corresponding to the current buffer. @end quotation @end ifnottex @noindent In this case, the text should be formatted with @code{@@table}, @code{@@item}, and @code{@@itemx}, to create a table. @subsubheading @@code, @@samp, @@var, and @samp{---} @itemize @bullet @item Use @code{@@code} around Lisp symbols, including command names. For example, @example The main function is @@code@{vc-next-action@}, @dots{} @end example @item Avoid putting letters such as @samp{s} immediately after an @samp{@@code}. Such letters look bad. @item Use @code{@@var} around meta-variables. Do not write angle brackets around them. @item Use three hyphens in a row, @samp{---}, to indicate a long dash. @TeX{} typesets these as a long dash and the Info formatters reduce three hyphens to two. @end itemize @subsubheading Periods Outside of Quotes Place periods and other punctuation marks @emph{outside} of quotations, unless the punctuation is part of the quotation. This practice goes against publishing conventions in the United States, but enables the reader to distinguish between the contents of the quotation and the whole passage. For example, you should write the following sentence with the period outside the end quotation marks: @example Evidently, @samp{au} is an abbreviation for ``author''. @end example @noindent since @samp{au} does @emph{not} serve as an abbreviation for @samp{author.} (with a period following the word). @subsubheading Introducing New Terms @itemize @bullet @item Introduce new terms so that a reader who does not know them can understand them from context; or write a definition for the term. For example, in the following, the terms ``check in'', ``register'' and ``delta'' are all appearing for the first time; the example sentence should be rewritten so they are understandable. @quotation The major function assists you in checking in a file to your version control system and registering successive sets of changes to it as deltas. @end quotation @item Use the @code{@@dfn} command around a word being introduced, to indicate that the reader should not expect to know the meaning already, and should expect to learn the meaning from this passage. @end itemize @subsubheading @@pxref @c !!! maybe include this in the tips on pxref @ignore By the way, it is okay to use pxref with something else in front of it within the parens, as long as the pxref is followed by the close paren, and the material inside the parens is not part of a larger sentence. Also, you can use xref inside parens as part of a complete sentence so long as you terminate the cross reference with punctuation. @end ignore Absolutely never use @code{@@pxref} except in the special context for which it is designed: inside parentheses, with the closing parenthesis following immediately after the closing brace. One formatter automatically inserts closing punctuation and the other does not. This means that the output looks right both in printed output and in an Info file, but only when the command is used inside parentheses. @subsubheading Invoking from a Shell You can invoke programs such as Emacs, GCC, and @code{gawk} from a shell. The documentation for each program should contain a section that describes this. Unfortunately, if the node names and titles for these sections are all different, they are difficult for users to find. So, there is a convention to name such sections with a phrase beginning with the word `Invoking', as in `Invoking Emacs'; this way, users can find the section easily. @subsubheading ANSI C Syntax When you use @code{@@example} to describe a C function's calling conventions, use the ANSI C syntax, like this:@refill @example void dld_init (char *@@var@{path@}); @end example @noindent And in the subsequent discussion, refer to the argument values by writing the same argument names, again highlighted with @code{@@var}.@refill @need 800 Avoid the obsolete style that looks like this:@refill @example #include <dld.h> dld_init (path) char *path; @end example Also, it is best to avoid writing @code{#include} above the declaration just to indicate that the function is declared in a header file. The practice may give the misimpression that the @code{#include} belongs near the declaration of the function. Either state explicitly which header file holds the declaration or, better yet, name the header file used for a group of functions at the beginning of the section that describes the functions.@refill @subsubheading Bad Examples Here are several examples of bad writing to avoid: In this example, say, `` @dots{} you must @code{@@dfn}@{check in@} the new version.'' That flows better. @quotation When you are done editing the file, you must perform a @code{@@dfn}@{check in@}. @end quotation In the following example, say, ``@dots{} makes a unified interface such as VC mode possible.'' @quotation SCCS, RCS and other version-control systems all perform similar functions in broadly similar ways (it is this resemblance which makes a unified control mode like this possible). @end quotation And in this example, you should specify what `it' refers to: @quotation If you are working with other people, it assists in coordinating everyone's changes so they do not step on each other. @end quotation @subsubheading And Finally @dots{} @itemize @bullet @item Pronounce @TeX{} as if the @samp{X} were a Greek `chi', as the last sound in the name `Bach'. But pronounce Texinfo as in `speck': ``teckinfo''. @item Write notes for yourself at the very end of a Texinfo file after the @code{@@bye}. None of the formatters process text after the @code{@@bye}; it is as if the text were within @code{@@ignore} @dots{} @code{@@end ignore}. @end itemize @node Sample Texinfo Files @appendix Sample Texinfo Files @cindex Sample Texinfo files The first example is from the first chapter (@pxref{Short Sample}), given here in its entirety, without commentary. The second includes the full texts to be used in GNU manuals. @menu * Short Sample Texinfo File:: * GNU Sample Texts:: * Verbatim Copying License:: * All-permissive Copying License:: @end menu @node Short Sample Texinfo File @section Short Sample @cindex Sample Texinfo file, no comments Here is a complete, short sample Texinfo file, without any commentary. You can see this file, with comments, in the first chapter. @xref{Short Sample}. In a nutshell: The @command{makeinfo} program transforms a Texinfo source file such as this into an Info file or HTML; and @TeX{} typesets it for a printed manual. @sp 1 @example \input texinfo @@c -*-texinfo-*- @@c %**start of header @@setfilename sample.info @@settitle Sample Manual 1.0 @@c %**end of header @@copying This is a short example of a complete Texinfo file. Copyright (C) 2004 Free Software Foundation, Inc. @@end copying @@titlepage @@title Sample Title @@page @@vskip 0pt plus 1filll @@insertcopying @@end titlepage @@c Output the table of the contents at the beginning. @@contents @@ifnottex @@node Top @@top GNU Sample @@insertcopying @@end ifnottex @@menu * First Chapter:: The first chapter is the only chapter in this sample. * Index:: Complete index. @@end menu @@node First Chapter @@chapter First Chapter @@cindex chapter, first This is the first chapter. @@cindex index entry, another Here is a numbered list. @@enumerate @@item This is the first item. @@item This is the second item. @@end enumerate @@node Index @@unnumbered Index @@printindex cp @@bye @end example @node GNU Sample Texts @section GNU Sample Texts @cindex GNU sample texts @cindex Sample texts, GNU @cindex Full texts, GNU Following is a sample Texinfo document with the full texts that should be used in GNU manuals. As well as the legal texts, it also serves as a practical example of how many elements in a GNU system can affect the manual. If you're not familiar with all these different elements, don't worry. They're not required and a perfectly good manual can be written without them. They're included here nonetheless because many manuals do (or could) benefit from them. @xref{Short Sample}, for a minimal example of a Texinfo file. @xref{Beginning a File}, for a full explanation of that minimal example. Here are some notes on the example: @itemize @bullet @item @cindex $Id @cindex CVS $Id @cindex RCS $Id @cindex Documentation identification @cindex Identification of documentation The @samp{$Id:} comment is for the CVS (@pxref{Top,, Overview, cvs, Concurrent Versions System}) or RCS (see rcsintro(1)) version control systems, which expand it into a string such as: @example Id: texinfo.txi,v 1.128 2004/12/29 15:06:41 karl Exp @end example (This is useful in all sources that use version control, not just manuals.) You may wish to include the @samp{$Id:} comment in the @code{@@copying} text, if you want a completely unambiguous reference to the documentation version. If you want to literally write @t{@w{$}Id$}, use @code{@@w}: @code{@@w@{$@}Id$}. @item @pindex automake@r{, and version info} @vindex UPDATED @r{Automake variable} @vindex VERSION @r{Automake variable} @pindex time-stamp.el The @file{version.texi} in the @code{@@include} command is maintained automatically by Automake (@pxref{Top,, Introduction, automake, GNU Automake}). It sets the @samp{VERSION} and @samp{UPDATED} values used elsewhere. If your distribution doesn't use Automake, but you do use Emacs, you may find the time-stamp.el package helpful (@pxref{Time Stamps,,,emacs,The GNU Emacs Manual}). @item The @code{@@syncodeindex} command reflects the recommendation to use only one index where possible, to make it easier for readers to look up index entries. @item The @code{@@dircategory} is for constructing the Info directory. @xref{Installing Dir Entries}, which includes a variety of recommended category names. @item The `Invoking' node is a GNU standard to help users find the basic information about command-line usage of a given program. @xref{Manual Structure Details,,,standards, GNU Coding Standards}. @item @cindex GNU Free Documentation License, including entire @cindex Free Documentation License, including entire It is best to include the entire GNU Free Documentation License in a GNU manual, unless the manual is only a few pages long. Of course this sample is even shorter than that, but it includes the FDL anyway in order to show one conventional way to do so. The @file{fdl.texi} file is available on the GNU machines and in the Texinfo and other GNU source distributions. The FDL provides for omitting itself under certain conditions, but in that case the sample texts given here have to be modified. @xref{GNU Free Documentation License}. @item If your manual has invariant sections (again, see the license itself for details), then don't forget to change the text here accordingly. @item For documents that express your personal views, feelings or experiences, it is more appropriate to use a license permitting only verbatim copying, rather than the FDL. @xref{Verbatim Copying License}. @end itemize Here is the sample document: @verbatim \input texinfo @c -*-texinfo-*- @comment Id: texinfo.txi,v 1.128 2004/12/29 15:06:41 karl Exp @comment %**start of header @setfilename sample.info @include version.texi @settitle GNU Sample @value{VERSION} @syncodeindex pg cp @comment %**end of header @copying This manual is for GNU Sample (version @value{VERSION}, @value{UPDATED}), which is an example in the Texinfo documentation. Copyright @copyright{} 2004 Free Software Foundation, Inc. @quotation Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with no Invariant Sections, with the Front-Cover Texts being ``A GNU Manual,'' and with the Back-Cover Texts as in (a) below. A copy of the license is included in the section entitled ``GNU Free Documentation License.'' (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development.'' @end quotation @end copying @dircategory Texinfo documentation system @direntry * sample: (sample)Invoking sample. @end direntry @titlepage @title GNU Sample @subtitle for version @value{VERSION}, @value{UPDATED} @author A.U. Thor (@email{bug-texinfo@@gnu.org}) @page @vskip 0pt plus 1filll @insertcopying @end titlepage @contents @ifnottex @node Top @top GNU Sample @insertcopying @end ifnottex @menu * Invoking sample:: * Copying This Manual:: * Index:: @end menu @node Invoking sample @chapter Invoking sample @pindex sample @cindex invoking @command{sample} This is a sample manual. There is no sample program to invoke, but if there was, you could see its basic usage and command line options here. @node Copying This Manual @appendix Copying This Manual @menu * GNU Free Documentation License:: License for copying this manual. @end menu @include fdl.texi @node Index @unnumbered Index @printindex cp @bye @end verbatim @node Verbatim Copying License @section Verbatim Copying License @cindex Verbatim copying license @cindex License for verbatim copying For software manuals and other documentation, it is important to use a license permitting free redistribution and updating, so that when a free program is changed, the documentation can be updated as well. On the other hand, for documents that express your personal views, feelings or experiences, it is more appropriate to use a license permitting only verbatim copying. Here is sample text for such a license permitting verbatim copying only. This is just the license text itself. For a complete sample document, see the previous sections. @verbatim @copying This document is a sample for allowing verbatim copying only. Copyright @copyright{} 2004 Free Software Foundation, Inc. @quotation Permission is granted to make and distribute verbatim copies of this entire document without royalty provided the copyright notice and this permission notice are preserved. @end quotation @end copying @end verbatim @node All-permissive Copying License @section All-permissive Copying License @cindex All-permissive copying license @cindex License for all-permissive copying For software manuals and other documentation, it is important to use a license permitting free redistribution and updating, so that when a free program is changed, the documentation can be updated as well. On the other hand, for small supporting files, short manuals (under 300 lines long) and rough documentation (README files, INSTALL files, etc.), the full FDL would be overkill. They can use a simple all-permissive license. Here is sample text for such an all-permissive license. This is just the license text itself. For a complete sample document, see the previous sections. @example Copyright @copyright{} 2004 Free Software Foundation, Inc. Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved. @end example @node Include Files @appendix Include Files @cindex Include files When @TeX{} or an Info formatting command sees an @code{@@include} command in a Texinfo file, it processes the contents of the file named by the command and incorporates them into the DVI or Info file being created. Index entries from the included file are incorporated into the indices of the output file. Include files let you keep a single large document as a collection of conveniently small parts. @menu * Using Include Files:: How to use the @code{@@include} command. * texinfo-multiple-files-update:: How to create and update nodes and menus when using included files. * Include Files Requirements:: @code{texinfo-multiple-files-update} needs. * Sample Include File:: A sample outer file with included files within it; and a sample included file. * Include Files Evolution:: How use of the @code{@@include} command has changed over time. @end menu @node Using Include Files @section How to Use Include Files @findex include To include another file within a Texinfo file, write the @code{@@include} command at the beginning of a line and follow it on the same line by the name of a file to be included. For example: @example @@include buffers.texi @end example The name of the file is taken literally, with a single exception: @code{@@value@{@var{var}@}} references are expanded. This makes it possible to reliably include files in other directories in a distribution. @xref{verbatiminclude,,@code{@@verbatiminclude}}, for an example. An included file should simply be a segment of text that you expect to be included as is into the overall or @dfn{outer} Texinfo file; it should not contain the standard beginning and end parts of a Texinfo file. In particular, you should not start an included file with a line saying @samp{\input texinfo}; if you do, that phrase is inserted into the output file as is. Likewise, you should not end an included file with an @code{@@bye} command; nothing after @code{@@bye} is formatted. In the past, you were required to write an @code{@@setfilename} line at the beginning of an included file, but no longer. Now, it does not matter whether you write such a line. If an @code{@@setfilename} line exists in an included file, it is ignored.@refill Conventionally, an included file begins with an @code{@@node} line that is followed by an @code{@@chapter} line. Each included file is one chapter. This makes it easy to use the regular node and menu creating and updating commands to create the node pointers and menus within the included file. However, the simple Emacs node and menu creating and updating commands do not work with multiple Texinfo files. Thus you cannot use these commands to fill in the `Next', `Previous', and `Up' pointers of the @code{@@node} line that begins the included file. Also, you cannot use the regular commands to create a master menu for the whole file. Either you must insert the menus and the `Next', `Previous', and `Up' pointers by hand, or you must use the GNU Emacs Texinfo mode command, @code{texinfo-multiple-files-update}, that is designed for @code{@@include} files.@refill When an included file does not have any node lines in it, the multiple files update command does not try to create a menu entry for it. Consequently, you can include any file, such as a version or an update file without node lines, not just files that are chapters. Small includable files like this are created by Automake (@pxref{GNU Sample Texts}). @node texinfo-multiple-files-update @section @code{texinfo-multiple-files-update} @findex texinfo-multiple-files-update GNU Emacs Texinfo mode provides the @code{texinfo-multiple-files-update} command. This command creates or updates `Next', `Previous', and `Up' pointers of included files as well as those in the outer or overall Texinfo file, and it creates or updates a main menu in the outer file. Depending whether you call it with optional arguments, the command updates only the pointers in the first @code{@@node} line of the included files or all of them:@refill @table @kbd @item M-x texinfo-multiple-files-update Called without any arguments:@refill @itemize @minus @item Create or update the `Next', `Previous', and `Up' pointers of the first @code{@@node} line in each file included in an outer or overall Texinfo file.@refill @item Create or update the `Top' level node pointers of the outer or overall file.@refill @item Create or update a main menu in the outer file.@refill @end itemize @item C-u M-x texinfo-multiple-files-update Called with @kbd{C-u} as a prefix argument: @itemize @minus{} @item Create or update pointers in the first @code{@@node} line in each included file. @item Create or update the `Top' level node pointers of the outer file. @item Create and insert a master menu in the outer file. The master menu is made from all the menus in all the included files.@refill @end itemize @item C-u 8 M-x texinfo-multiple-files-update Called with a numeric prefix argument, such as @kbd{C-u 8}: @itemize @minus @item Create or update @strong{all} the `Next', `Previous', and `Up' pointers of all the included files.@refill @item Create or update @strong{all} the menus of all the included files.@refill @item Create or update the `Top' level node pointers of the outer or overall file.@refill @item And then create a master menu in the outer file. This is similar to invoking @code{texinfo-master-menu} with an argument when you are working with just one file.@refill @end itemize @end table Note the use of the prefix argument in interactive use: with a regular prefix argument, just @w{@kbd{C-u}}, the @code{texinfo-multiple-files-update} command inserts a master menu; with a numeric prefix argument, such as @kbd{C-u 8}, the command updates @strong{every} pointer and menu in @strong{all} the files and then inserts a master menu.@refill @node Include Files Requirements @section Include Files Requirements @cindex Include files requirements @cindex Requirements for include files If you plan to use the @code{texinfo-multiple-files-update} command, the outer Texinfo file that lists included files within it should contain nothing but the beginning and end parts of a Texinfo file, and a number of @code{@@include} commands listing the included files. It should not even include indices, which should be listed in an included file of their own.@refill Moreover, each of the included files must contain exactly one highest level node (conventionally, @code{@@chapter} or equivalent), and this node must be the first node in the included file. Furthermore, each of these highest level nodes in each included file must be at the same hierarchical level in the file structure. Usually, each is an @code{@@chapter}, an @code{@@appendix}, or an @code{@@unnumbered} node. Thus, normally, each included file contains one, and only one, chapter or equivalent-level node.@refill The outer file should contain only @emph{one} node, the `Top' node. It should @emph{not} contain any nodes besides the single `Top' node. The @code{texinfo-multiple-files-update} command will not process them.@refill @node Sample Include File @section Sample File with @code{@@include} @cindex Sample @code{@@include} file @cindex Include file sample @cindex @code{@@include} file sample Here is an example of an outer Texinfo file with @code{@@include} files within it before running @code{texinfo-multiple-files-update}, which would insert a main or master menu: @example @group \input texinfo @@c -*-texinfo-*- @c %**start of header @@setfilename include-example.info @@settitle Include Example @c %**end of header @end group ... @xref{Sample Texinfo Files}, for examples of the rest of the frontmatter ... @group @@ifnottex @@node Top @@top Include Example @@end ifnottex @end group @group @@include foo.texinfo @@include bar.texinfo @@include concept-index.texinfo @@bye @end group @end example An included file, such as @file{foo.texinfo}, might look like this: @example @group @@node First @@chapter First Chapter Contents of first chapter @dots{} @end group @end example The full contents of @file{concept-index.texinfo} might be as simple as this: @example @group @@node Concept Index @@unnumbered Concept Index @@printindex cp @end group @end example The outer Texinfo source file for @cite{The GNU Emacs Lisp Reference Manual} is named @file{elisp.texi}. This outer file contains a master menu with 417 entries and a list of 41 @code{@@include} files. @node Include Files Evolution @section Evolution of Include Files When Info was first created, it was customary to create many small Info files on one subject. Each Info file was formatted from its own Texinfo source file. This custom meant that Emacs did not need to make a large buffer to hold the whole of a large Info file when someone wanted information; instead, Emacs allocated just enough memory for the small Info file that contained the particular information sought. This way, Emacs could avoid wasting memory.@refill References from one file to another were made by referring to the file name as well as the node name. (@xref{Other Info Files, , Referring to Other Info Files}. Also, see @ref{Four and Five Arguments, , @code{@@xref} with Four and Five Arguments}.)@refill Include files were designed primarily as a way to create a single, large printed manual out of several smaller Info files. In a printed manual, all the references were within the same document, so @TeX{} could automatically determine the references' page numbers. The Info formatting commands used include files only for creating joint indices; each of the individual Texinfo files had to be formatted for Info individually. (Each, therefore, required its own @code{@@setfilename} line.)@refill However, because large Info files are now split automatically, it is no longer necessary to keep them small.@refill Nowadays, multiple Texinfo files are used mostly for large documents, such as @cite{The GNU Emacs Lisp Reference Manual}, and for projects in which several different people write different sections of a document simultaneously.@refill In addition, the Info formatting commands have been extended to work with the @code{@@include} command so as to create a single large Info file that is split into smaller files if necessary. This means that you can write menus and cross references without naming the different Texinfo files.@refill @node Headings @appendix Page Headings @cindex Headings @cindex Footings @cindex Page numbering @cindex Page headings @cindex Formatting headings and footings Most printed manuals contain headings along the top of every page except the title and copyright pages. Some manuals also contain footings. (Headings and footings have no meaning to Info, which is not paginated.)@refill @menu * Headings Introduced:: Conventions for using page headings. * Heading Format:: Standard page heading formats. * Heading Choice:: How to specify the type of page heading. * Custom Headings:: How to create your own headings and footings. @end menu @node Headings Introduced @section Headings Introduced Texinfo provides standard page heading formats for manuals that are printed on one side of each sheet of paper and for manuals that are printed on both sides of the paper. Typically, you will use these formats, but you can specify your own format if you wish.@refill In addition, you can specify whether chapters should begin on a new page, or merely continue the same page as the previous chapter; and if chapters begin on new pages, you can specify whether they must be odd-numbered pages.@refill By convention, a book is printed on both sides of each sheet of paper. When you open a book, the right-hand page is odd-numbered, and chapters begin on right-hand pages---a preceding left-hand page is left blank if necessary. Reports, however, are often printed on just one side of paper, and chapters begin on a fresh page immediately following the end of the preceding chapter. In short or informal reports, chapters often do not begin on a new page at all, but are separated from the preceding text by a small amount of whitespace.@refill The @code{@@setchapternewpage} command controls whether chapters begin on new pages, and whether one of the standard heading formats is used. In addition, Texinfo has several heading and footing commands that you can use to generate your own heading and footing formats.@refill In Texinfo, headings and footings are single lines at the tops and bottoms of pages; you cannot create multiline headings or footings. Each header or footer line is divided into three parts: a left part, a middle part, and a right part. Any part, or a whole line, may be left blank. Text for the left part of a header or footer line is set flushleft; text for the middle part is centered; and, text for the right part is set flushright.@refill @node Heading Format @comment node-name, next, previous, up @section Standard Heading Formats Texinfo provides two standard heading formats, one for manuals printed on one side of each sheet of paper, and the other for manuals printed on both sides of the paper. By default, nothing is specified for the footing of a Texinfo file, so the footing remains blank.@refill The standard format for single-sided printing consists of a header line in which the left-hand part contains the name of the chapter, the central part is blank, and the right-hand part contains the page number.@refill @need 950 A single-sided page looks like this: @example @group _______________________ | | | chapter page number | | | | Start of text ... | | ... | | | @end group @end example The standard format for two-sided printing depends on whether the page number is even or odd. By convention, even-numbered pages are on the left- and odd-numbered pages are on the right. (@TeX{} will adjust the widths of the left- and right-hand margins. Usually, widths are correct, but during double-sided printing, it is wise to check that pages will bind properly---sometimes a printer will produce output in which the even-numbered pages have a larger right-hand margin than the odd-numbered pages.)@refill In the standard double-sided format, the left part of the left-hand (even-numbered) page contains the page number, the central part is blank, and the right part contains the title (specified by the @code{@@settitle} command). The left part of the right-hand (odd-numbered) page contains the name of the chapter, the central part is blank, and the right part contains the page number.@refill @need 750 Two pages, side by side as in an open book, look like this:@refill @example @group _______________________ _______________________ | | | | | page number title | | chapter page number | | | | | | Start of text ... | | More text ... | | ... | | ... | | | | | @end group @end example @noindent The chapter name is preceded by the word ``Chapter'', the chapter number and a colon. This makes it easier to keep track of where you are in the manual.@refill @node Heading Choice @comment node-name, next, previous, up @section Specifying the Type of Heading @TeX{} does not begin to generate page headings for a standard Texinfo file until it reaches the @code{@@end titlepage} command. Thus, the title and copyright pages are not numbered. The @code{@@end titlepage} command causes @TeX{} to begin to generate page headings according to a standard format specified by the @code{@@setchapternewpage} command that precedes the @code{@@titlepage} section.@refill @need 1000 There are four possibilities:@refill @table @asis @item No @code{@@setchapternewpage} command Cause @TeX{} to specify the single-sided heading format, with chapters on new pages. This is the same as @code{@@setchapternewpage on}.@refill @item @code{@@setchapternewpage on} Specify the single-sided heading format, with chapters on new pages.@refill @item @code{@@setchapternewpage off} Cause @TeX{} to start a new chapter on the same page as the last page of the preceding chapter, after skipping some vertical whitespace. Also cause @TeX{} to typeset for single-sided printing. (You can override the headers format with the @code{@@headings double} command; see @ref{headings on off, , The @code{@@headings} Command}.)@refill @item @code{@@setchapternewpage odd} Specify the double-sided heading format, with chapters on new pages.@refill @end table @noindent Texinfo lacks an @code{@@setchapternewpage even} command.@refill @node Custom Headings @comment node-name, next, previous, up @section How to Make Your Own Headings You can use the standard headings provided with Texinfo or specify your own. By default, Texinfo has no footers, so if you specify them, the available page size for the main text will be slightly reduced. Texinfo provides six commands for specifying headings and footings: @itemize @bullet @item @code{@@everyheading} @code{@@everyfooting} generate page headers and footers that are the same for both even- and odd-numbered pages. @item @code{@@evenheading} and @code{@@evenfooting} command generate headers and footers for even-numbered (left-hand) pages. @item @code{@@oddheading} and @code{@@oddfooting} generate headers and footers for odd-numbered (right-hand) pages. @end itemize Write custom heading specifications in the Texinfo file immediately after the @code{@@end titlepage} command. You must cancel the predefined heading commands with the @code{@@headings off} command before defining your own specifications.@refill @need 1000 Here is how to tell @TeX{} to place the chapter name at the left, the page number in the center, and the date at the right of every header for both even- and odd-numbered pages:@refill @example @group @@headings off @@everyheading @@thischapter @@| @@thispage @@| @@today@{@} @end group @end example @noindent You need to divide the left part from the central part and the central part from the right part by inserting @samp{@@|} between parts. Otherwise, the specification command will not be able to tell where the text for one part ends and the next part begins.@refill Each part can contain text or @@-commands. The text is printed as if the part were within an ordinary paragraph in the body of the page. The @@-commands replace themselves with the page number, date, chapter name, or whatever.@refill @need 950 Here are the six heading and footing commands:@refill @findex everyheading @findex everyfooting @table @code @item @@everyheading @var{left} @@| @var{center} @@| @var{right} @itemx @@everyfooting @var{left} @@| @var{center} @@| @var{right} The `every' commands specify the format for both even- and odd-numbered pages. These commands are for documents that are printed on one side of each sheet of paper, or for documents in which you want symmetrical headers or footers.@refill @findex evenheading @findex evenfooting @findex oddheading @findex oddfooting @item @@evenheading @var{left} @@| @var{center} @@| @var{right} @itemx @@oddheading @var{left} @@| @var{center} @@| @var{right} @itemx @@evenfooting @var{left} @@| @var{center} @@| @var{right} @itemx @@oddfooting @var{left} @@| @var{center} @@| @var{right} The `even' and `odd' commands specify the format for even-numbered pages and odd-numbered pages. These commands are for books and manuals that are printed on both sides of each sheet of paper. @end table Use the @samp{@@this@dots{}} series of @@-commands to provide the names of chapters and sections and the page number. You can use the @samp{@@this@dots{}} commands in the left, center, or right portions of headers and footers, or anywhere else in a Texinfo file so long as they are between @code{@@iftex} and @code{@@end iftex} commands.@refill @need 1000 Here are the @samp{@@this@dots{}} commands:@refill @table @code @findex thispage @item @@thispage Expands to the current page number.@refill @c !!! Karl Berry says that `thissection' can fail on page breaks. @ignore @item @@thissection Expands to the name of the current section.@refill @end ignore @findex thischaptername @item @@thischaptername Expands to the name of the current chapter.@refill @findex thischapter @item @@thischapter Expands to the number and name of the current chapter, in the format `Chapter 1: Title'.@refill @findex thistitle @item @@thistitle Expands to the name of the document, as specified by the @code{@@settitle} command.@refill @findex thisfile @item @@thisfile For @code{@@include} files only: expands to the name of the current @code{@@include} file. If the current Texinfo source file is not an @code{@@include} file, this command has no effect. This command does @emph{not} provide the name of the current Texinfo source file unless it is an @code{@@include} file. (@xref{Include Files}, for more information about @code{@@include} files.)@refill @end table @noindent You can also use the @code{@@today@{@}} command, which expands to the current date, in `1 Jan 1900' format.@refill @findex today Other @@-commands and text are printed in a header or footer just as if they were in the body of a page. It is useful to incorporate text, particularly when you are writing drafts:@refill @example @group @@headings off @@everyheading @@emph@{Draft!@} @@| @@thispage @@| @@thischapter @@everyfooting @@| @@| Version: 0.27: @@today@{@} @end group @end example Beware of overlong titles: they may overlap another part of the header or footer and blot it out.@refill @node Catching Mistakes @appendix Formatting Mistakes @cindex Structure, catching mistakes in @cindex Nodes, catching mistakes @cindex Catching mistakes @cindex Correcting mistakes @cindex Mistakes, catching @cindex Problems, catching @cindex Debugging the Texinfo structure Besides mistakes in the content of your documentation, there are two kinds of mistake you can make with Texinfo: you can make mistakes with @@-commands, and you can make mistakes with the structure of the nodes and chapters. Emacs has two tools for catching the @@-command mistakes and two for catching structuring mistakes.@refill For finding problems with @@-commands, you can run @TeX{} or a region formatting command on the region that has a problem; indeed, you can run these commands on each region as you write it.@refill For finding problems with the structure of nodes and chapters, you can use @kbd{C-c C-s} (@code{texinfo-show-structure}) and the related @code{occur} command and you can use the @kbd{M-x Info-validate} command.@refill @menu * makeinfo Preferred:: @code{makeinfo} finds errors. * Debugging with Info:: How to catch errors with Info formatting. * Debugging with TeX:: How to catch errors with @TeX{} formatting. * Using texinfo-show-structure:: How to use @code{texinfo-show-structure}. * Using occur:: How to list all lines containing a pattern. * Running Info-Validate:: How to find badly referenced nodes. @end menu @node makeinfo Preferred @section @code{makeinfo} Find Errors The @code{makeinfo} program does an excellent job of catching errors and reporting them---far better than @code{texinfo-format-region} or @code{texinfo-format-buffer}. In addition, the various functions for automatically creating and updating node pointers and menus remove many opportunities for human error.@refill If you can, use the updating commands to create and insert pointers and menus. These prevent many errors. Then use @code{makeinfo} (or its Texinfo mode manifestations, @code{makeinfo-region} and @code{makeinfo-buffer}) to format your file and check for other errors. This is the best way to work with Texinfo. But if you cannot use @code{makeinfo}, or your problem is very puzzling, then you may want to use the tools described in this appendix.@refill @node Debugging with Info @comment node-name, next, previous, up @section Catching Errors with Info Formatting @cindex Catching errors with Info formatting @cindex Debugging with Info formatting After you have written part of a Texinfo file, you can use the @code{texinfo-format-region} or the @code{makeinfo-region} command to see whether the region formats properly.@refill Most likely, however, you are reading this section because for some reason you cannot use the @code{makeinfo-region} command; therefore, the rest of this section presumes that you are using @code{texinfo-format-region}.@refill If you have made a mistake with an @@-command, @code{texinfo-format-region} will stop processing at or after the error and display an error message. To see where in the buffer the error occurred, switch to the @samp{*Info Region*} buffer; the cursor will be in a position that is after the location of the error. Also, the text will not be formatted after the place where the error occurred (or more precisely, where it was detected).@refill For example, if you accidentally end a menu with the command @code{@@end menus} with an `s' on the end, instead of with @code{@@end menu}, you will see an error message that says:@refill @example @@end menus is not handled by texinfo @end example @noindent The cursor will stop at the point in the buffer where the error occurs, or not long after it. The buffer will look like this:@refill @example @group ---------- Buffer: *Info Region* ---------- * Menu: * Using texinfo-show-structure:: How to use `texinfo-show-structure' to catch mistakes. * Running Info-Validate:: How to check for unreferenced nodes. @@end menus @point{} ---------- Buffer: *Info Region* ---------- @end group @end example The @code{texinfo-format-region} command sometimes provides slightly odd error messages. For example, the following cross reference fails to format:@refill @example (@@xref@{Catching Mistakes, for more info.) @end example @noindent In this case, @code{texinfo-format-region} detects the missing closing brace but displays a message that says @samp{Unbalanced parentheses} rather than @samp{Unbalanced braces}. This is because the formatting command looks for mismatches between braces as if they were parentheses.@refill Sometimes @code{texinfo-format-region} fails to detect mistakes. For example, in the following, the closing brace is swapped with the closing parenthesis:@refill @example (@@xref@{Catching Mistakes), for more info.@} @end example @noindent Formatting produces: @example (*Note for more info.: Catching Mistakes) @end example The only way for you to detect this error is to realize that the reference should have looked like this:@refill @example (*Note Catching Mistakes::, for more info.) @end example Incidentally, if you are reading this node in Info and type @kbd{f @key{RET}} (@code{Info-follow-reference}), you will generate an error message that says: @example No such node: "Catching Mistakes) The only way @dots{} @end example @noindent This is because Info perceives the example of the error as the first cross reference in this node and if you type a @key{RET} immediately after typing the Info @kbd{f} command, Info will attempt to go to the referenced node. If you type @kbd{f catch @key{TAB} @key{RET}}, Info will complete the node name of the correctly written example and take you to the `Catching Mistakes' node. (If you try this, you can return from the `Catching Mistakes' node by typing @kbd{l} (@code{Info-last}).) @c !!! section on using Elisp debugger ignored. @ignore Sometimes @code{texinfo-format-region} will stop long after the original error; this is because it does not discover the problem until then. In this case, you will need to backtrack.@refill @c menu @c * Using the Emacs Lisp Debugger:: How to use the Emacs Lisp debugger. @c end menu @c node Using the Emacs Lisp Debugger @c appendixsubsec Using the Emacs Lisp Debugger @c index Using the Emacs Lisp debugger @c index Emacs Lisp debugger @c index Debugger, using the Emacs Lisp If an error is especially elusive, you can turn on the Emacs Lisp debugger and look at the backtrace; this tells you where in the @code{texinfo-format-region} function the problem occurred. You can turn on the debugger with the command:@refill @example M-x set-variable @key{RET} debug-on-error @key{RET} t @key{RET} @end example @noindent and turn it off with @example M-x set-variable @key{RET} debug-on-error @key{RET} nil @key{RET} @end example Often, when you are using the debugger, it is easier to follow what is going on if you use the Emacs Lisp files that are not byte-compiled. The byte-compiled sources send octal numbers to the debugger that may look mysterious. To use the uncompiled source files, load @file{texinfmt.el} and @file{texinfo.el} with the @kbd{M-x load-file} command.@refill The debugger will not catch an error if @code{texinfo-format-region} does not detect one. In the example shown above, @code{texinfo-format-region} did not find the error when the whole list was formatted, but only when part of the list was formatted. When @code{texinfo-format-region} did not find an error, the debugger did not find one either. @refill However, when @code{texinfo-format-region} did report an error, it invoked the debugger. This is the backtrace it produced:@refill @example ---------- Buffer: *Backtrace* ---------- Signalling: (search-failed "[@},]") re-search-forward("[@},]") (while ...) (let ...) texinfo-format-parse-args() (let ...) texinfo-format-xref() funcall(texinfo-format-xref) (if ...) (let ...) (if ...) (while ...) texinfo-format-scan() (save-excursion ...) (let ...) texinfo-format-region(103370 103631) * call-interactively(texinfo-format-region) ---------- Buffer: *Backtrace* ---------- @end example The backtrace is read from the bottom up. @code{texinfo-format-region} was called interactively; and it, in turn, called various functions, including @code{texinfo-format-scan}, @code{texinfo-format-xref} and @code{texinfo-format-parse-args}. Inside the function @code{texinfo-format-parse-args}, the function @code{re-search-forward} was called; it was this function that could not find the missing right-hand brace.@refill @xref{Lisp Debug, , Debugging Emacs Lisp, emacs, The GNU Emacs Manual}, for more information.@refill @end ignore @node Debugging with TeX @comment node-name, next, previous, up @section Catching Errors with @TeX{} Formatting @cindex Catching errors with @TeX{} formatting @cindex Debugging with @TeX{} formatting You can also catch mistakes when you format a file with @TeX{}.@refill Usually, you will want to do this after you have run @code{texinfo-format-buffer} (or, better, @code{makeinfo-buffer}) on the same file, because @code{texinfo-format-buffer} sometimes displays error messages that make more sense than @TeX{}. (@xref{Debugging with Info}, for more information.)@refill For example, @TeX{} was run on a Texinfo file, part of which is shown here:@refill @example ---------- Buffer: texinfo.texi ---------- name of the Texinfo file as an extension. The @@samp@{??@} are `wildcards' that cause the shell to substitute all the raw index files. (@@xref@{sorting indices, for more information about sorting indices.)@@refill ---------- Buffer: texinfo.texi ---------- @end example @noindent (The cross reference lacks a closing brace.) @TeX{} produced the following output, after which it stopped:@refill @example ---------- Buffer: *tex-shell* ---------- Runaway argument? @{sorting indices, for more information about sorting indices.) @@refill @@ETC. ! Paragraph ended before @@xref was complete. <to be read again> @@par l.27 ? ---------- Buffer: *tex-shell* ---------- @end example In this case, @TeX{} produced an accurate and understandable error message: @example Paragraph ended before @@xref was complete. @end example @noindent @samp{@@par} is an internal @TeX{} command of no relevance to Texinfo. @samp{l.27} means that @TeX{} detected the problem on line 27 of the Texinfo file. The @samp{?} is the prompt @TeX{} uses in this circumstance.@refill Unfortunately, @TeX{} is not always so helpful, and sometimes you must truly be a Sherlock Holmes to discover what went wrong.@refill In any case, if you run into a problem like this, you can do one of three things.@refill @enumerate @item You can tell @TeX{} to continue running and ignore just this error by typing @key{RET} at the @samp{?} prompt.@refill @item You can tell @TeX{} to continue running and to ignore all errors as best it can by typing @kbd{r @key{RET}} at the @samp{?} prompt.@refill This is often the best thing to do. However, beware: the one error may produce a cascade of additional error messages as its consequences are felt through the rest of the file. To stop @TeX{} when it is producing such an avalanche of error messages, type @kbd{C-c} (or @kbd{C-c C-c}, if you are running a shell inside Emacs). @item You can tell @TeX{} to stop this run by typing @kbd{x @key{RET}} at the @samp{?} prompt.@refill @end enumerate If you are running @TeX{} inside Emacs, you need to switch to the shell buffer and line at which @TeX{} offers the @samp{?} prompt. Sometimes @TeX{} will format a file without producing error messages even though there is a problem. This usually occurs if a command is not ended but @TeX{} is able to continue processing anyhow. For example, if you fail to end an itemized list with the @code{@@end itemize} command, @TeX{} will write a DVI file that you can print out. The only error message that @TeX{} will give you is the somewhat mysterious comment that@refill @example (@@end occurred inside a group at level 1) @end example @noindent However, if you print the DVI file, you will find that the text of the file that follows the itemized list is entirely indented as if it were part of the last item in the itemized list. The error message is the way @TeX{} says that it expected to find an @code{@@end} command somewhere in the file; but that it could not determine where it was needed.@refill Another source of notoriously hard-to-find errors is a missing @code{@@end group} command. If you ever are stumped by incomprehensible errors, look for a missing @code{@@end group} command first.@refill If the Texinfo file lacks header lines, @TeX{} may stop in the beginning of its run and display output that looks like the following. The @samp{*} indicates that @TeX{} is waiting for input.@refill @example This is TeX, Version 3.14159 (Web2c 7.0) (test.texinfo [1]) * @end example @noindent In this case, simply type @kbd{\end @key{RET}} after the asterisk. Then write the header lines in the Texinfo file and run the @TeX{} command again. (Note the use of the backslash, @samp{\}. @TeX{} uses @samp{\} instead of @samp{@@}; and in this circumstance, you are working directly with @TeX{}, not with Texinfo.)@refill @node Using texinfo-show-structure @comment node-name, next, previous, up @section Using @code{texinfo-show-structure} @cindex Showing the structure of a file @findex texinfo-show-structure It is not always easy to keep track of the nodes, chapters, sections, and subsections of a Texinfo file. This is especially true if you are revising or adding to a Texinfo file that someone else has written.@refill In GNU Emacs, in Texinfo mode, the @code{texinfo-show-structure} command lists all the lines that begin with the @@-commands that specify the structure: @code{@@chapter}, @code{@@section}, @code{@@appendix}, and so on. With an argument (@w{@kbd{C-u}} as prefix argument, if interactive), the command also shows the @code{@@node} lines. The @code{texinfo-show-structure} command is bound to @kbd{C-c C-s} in Texinfo mode, by default.@refill The lines are displayed in a buffer called the @samp{*Occur*} buffer, indented by hierarchical level. For example, here is a part of what was produced by running @code{texinfo-show-structure} on this manual:@refill @example @group Lines matching "^@@\\(chapter \\|sect\\|subs\\|subh\\| unnum\\|major\\|chapheading \\|heading \\|appendix\\)" in buffer texinfo.texi. @dots{} 4177:@@chapter Nodes 4198: @@heading Two Paths 4231: @@section Node and Menu Illustration 4337: @@section The @@code@{@@@@node@} Command 4393: @@subheading Choosing Node and Pointer Names 4417: @@subsection How to Write an @@code@{@@@@node@} Line 4469: @@subsection @@code@{@@@@node@} Line Tips @dots{} @end group @end example This says that lines 4337, 4393, and 4417 of @file{texinfo.texi} begin with the @code{@@section}, @code{@@subheading}, and @code{@@subsection} commands respectively. If you move your cursor into the @samp{*Occur*} window, you can position the cursor over one of the lines and use the @kbd{C-c C-c} command (@code{occur-mode-goto-occurrence}), to jump to the corresponding spot in the Texinfo file. @xref{Other Repeating Search, , Using Occur, emacs, The GNU Emacs Manual}, for more information about @code{occur-mode-goto-occurrence}.@refill The first line in the @samp{*Occur*} window describes the @dfn{regular expression} specified by @var{texinfo-heading-pattern}. This regular expression is the pattern that @code{texinfo-show-structure} looks for. @xref{Regexps, , Using Regular Expressions, emacs, The GNU Emacs Manual}, for more information.@refill When you invoke the @code{texinfo-show-structure} command, Emacs will display the structure of the whole buffer. If you want to see the structure of just a part of the buffer, of one chapter, for example, use the @kbd{C-x n n} (@code{narrow-to-region}) command to mark the region. (@xref{Narrowing, , , emacs, The GNU Emacs Manual}.) This is how the example used above was generated. (To see the whole buffer again, use @kbd{C-x n w} (@code{widen}).)@refill If you call @code{texinfo-show-structure} with a prefix argument by typing @w{@kbd{C-u C-c C-s}}, it will list lines beginning with @code{@@node} as well as the lines beginning with the @@-sign commands for @code{@@chapter}, @code{@@section}, and the like.@refill You can remind yourself of the structure of a Texinfo file by looking at the list in the @samp{*Occur*} window; and if you have mis-named a node or left out a section, you can correct the mistake.@refill @node Using occur @comment node-name, next, previous, up @section Using @code{occur} @cindex Occurrences, listing with @code{@@occur} @findex occur Sometimes the @code{texinfo-show-structure} command produces too much information. Perhaps you want to remind yourself of the overall structure of a Texinfo file, and are overwhelmed by the detailed list produced by @code{texinfo-show-structure}. In this case, you can use the @code{occur} command directly. To do this, type@refill @example @kbd{M-x occur} @end example @noindent and then, when prompted, type a @dfn{regexp}, a regular expression for the pattern you want to match. (@xref{Regexps, , Regular Expressions, emacs, The GNU Emacs Manual}.) The @code{occur} command works from the current location of the cursor in the buffer to the end of the buffer. If you want to run @code{occur} on the whole buffer, place the cursor at the beginning of the buffer.@refill For example, to see all the lines that contain the word @samp{@@chapter} in them, just type @samp{@@chapter}. This will produce a list of the chapters. It will also list all the sentences with @samp{@@chapter} in the middle of the line.@refill If you want to see only those lines that start with the word @samp{@@chapter}, type @samp{^@@chapter} when prompted by @code{occur}. If you want to see all the lines that end with a word or phrase, end the last word with a @samp{$}; for example, @samp{catching mistakes$}. This can be helpful when you want to see all the nodes that are part of the same chapter or section and therefore have the same `Up' pointer.@refill @xref{Other Repeating Search, , Using Occur, emacs , The GNU Emacs Manual}, for more information.@refill @node Running Info-Validate @comment node-name, next, previous, up @section Finding Badly Referenced Nodes @findex Info-validate @cindex Nodes, checking for badly referenced @cindex Checking for badly referenced nodes @cindex Looking for badly referenced nodes @cindex Finding badly referenced nodes @cindex Badly referenced nodes You can use the @code{Info-validate} command to check whether any of the `Next', `Previous', `Up' or other node pointers fail to point to a node. This command checks that every node pointer points to an existing node. The @code{Info-validate} command works only on Info files, not on Texinfo files.@refill The @code{makeinfo} program validates pointers automatically, so you do not need to use the @code{Info-validate} command if you are using @code{makeinfo}. You only may need to use @code{Info-validate} if you are unable to run @code{makeinfo} and instead must create an Info file using @code{texinfo-format-region} or @code{texinfo-format-buffer}, or if you write an Info file from scratch.@refill @menu * Using Info-validate:: How to run @code{Info-validate}. * Unsplit:: How to create an unsplit file. * Tagifying:: How to tagify a file. * Splitting:: How to split a file manually. @end menu @node Using Info-validate @subsection Running @code{Info-validate} @cindex Running @code{Info-validate} @cindex Info validating a large file @cindex Validating a large file To use @code{Info-validate}, visit the Info file you wish to check and type:@refill @example M-x Info-validate @end example @noindent Note that the @code{Info-validate} command requires an upper case `I'. You may also need to create a tag table before running @code{Info-validate}. @xref{Tagifying}. If your file is valid, you will receive a message that says ``File appears valid''. However, if you have a pointer that does not point to a node, error messages will be displayed in a buffer called @samp{*problems in info file*}.@refill For example, @code{Info-validate} was run on a test file that contained only the first node of this manual. One of the messages said:@refill @example In node "Overview", invalid Next: Texinfo Mode @end example @noindent This meant that the node called @samp{Overview} had a `Next' pointer that did not point to anything (which was true in this case, since the test file had only one node in it).@refill Now suppose we add a node named @samp{Texinfo Mode} to our test case but we do not specify a `Previous' for this node. Then we will get the following error message:@refill @example In node "Texinfo Mode", should have Previous: Overview @end example @noindent This is because every `Next' pointer should be matched by a `Previous' (in the node where the `Next' points) which points back.@refill @code{Info-validate} also checks that all menu entries and cross references point to actual nodes.@refill @code{Info-validate} requires a tag table and does not work with files that have been split. (The @code{texinfo-format-buffer} command automatically splits large files.) In order to use @code{Info-validate} on a large file, you must run @code{texinfo-format-buffer} with an argument so that it does not split the Info file; and you must create a tag table for the unsplit file. @node Unsplit @comment node-name, next, previous, up @subsection Creating an Unsplit File @cindex Creating an unsplit file @cindex Unsplit file creation You can run @code{Info-validate} only on a single Info file that has a tag table. The command will not work on the indirect subfiles that are generated when a master file is split. If you have a large file (longer than 300,000 bytes or so), you need to run the @code{texinfo-format-buffer} or @code{makeinfo-buffer} command in such a way that it does not create indirect subfiles. You will also need to create a tag table for the Info file. After you have done this, you can run @code{Info-validate} and look for badly referenced nodes.@refill The first step is to create an unsplit Info file. To prevent @code{texinfo-format-buffer} from splitting a Texinfo file into smaller Info files, give a prefix to the @kbd{M-x texinfo-format-buffer} command:@refill @example C-u M-x texinfo-format-buffer @end example @noindent or else @example C-u C-c C-e C-b @end example @noindent When you do this, Texinfo will not split the file and will not create a tag table for it. @refill @cindex Making a tag table manually @cindex Tag table, making manually @node Tagifying @subsection Tagifying a File After creating an unsplit Info file, you must create a tag table for it. Visit the Info file you wish to tagify and type:@refill @example M-x Info-tagify @end example @noindent (Note the upper case @samp{I} in @code{Info-tagify}.) This creates an Info file with a tag table that you can validate.@refill The third step is to validate the Info file:@refill @example M-x Info-validate @end example @noindent (Note the upper case @samp{I} in @code{Info-validate}.) In brief, the steps are:@refill @example @group C-u M-x texinfo-format-buffer M-x Info-tagify M-x Info-validate @end group @end example After you have validated the node structure, you can rerun @code{texinfo-format-buffer} in the normal way so it will construct a tag table and split the file automatically, or you can make the tag table and split the file manually.@refill @node Splitting @comment node-name, next, previous, up @subsection Splitting a File Manually @cindex Splitting an Info file manually @cindex Info file, splitting manually You should split a large file or else let the @code{texinfo-format-buffer} or @code{makeinfo-buffer} command do it for you automatically. (Generally you will let one of the formatting commands do this job for you. @xref{Creating an Info File}.)@refill The split-off files are called the indirect subfiles.@refill Info files are split to save memory. With smaller files, Emacs does not have make such a large buffer to hold the information.@refill If an Info file has more than 30 nodes, you should also make a tag table for it. @xref{Using Info-validate}, for information about creating a tag table. (Again, tag tables are usually created automatically by the formatting command; you only need to create a tag table yourself if you are doing the job manually. Most likely, you will do this for a large, unsplit file on which you have run @code{Info-validate}.)@refill @c Info-split is autoloaded in `loaddefs.el' in Emacs 18.51 @ignore Before running @code{Info-split}, you need to load the @code{info} library into Emacs by giving the command @kbd{M-x load-library @key{RET} info @key{RET}}. @end ignore Visit the Info file you wish to tagify and split and type the two commands:@refill @example M-x Info-tagify M-x Info-split @end example @noindent (Note that the @samp{I} in @samp{Info} is upper case.)@refill When you use the @code{Info-split} command, the buffer is modified into a (small) Info file which lists the indirect subfiles. This file should be saved in place of the original visited file. The indirect subfiles are written in the same directory the original file is in, with names generated by appending @samp{-} and a number to the original file name.@refill The primary file still functions as an Info file, but it contains just the tag table and a directory of subfiles.@refill @ignore The simple description in the command summary seems sufficient to me these days, so ignore this appendix. --karl, 13mar04. @node Refilling Paragraphs @appendix Refilling Paragraphs @cindex Refilling paragraphs @cindex Filling paragraphs @cindex Paragraphs, filling @findex refill The @code{@@refill} command refills and, optionally, indents the first line of a paragraph.@footnote{Perhaps the command should have been called the @code{@@refillandindent} command, but @code{@@refill} is shorter and the name was chosen before indenting was possible.} The @code{@@refill} command is no longer important, but we describe it here because you once needed it. You will see it in many old Texinfo files.@refill Without refilling, paragraphs containing long @@-constructs may look bad after formatting because the formatter removes @@-commands and shortens some lines more than others. In the past, neither the @code{texinfo-format-region} command nor the @code{texinfo-format-buffer} command refilled paragraphs automatically. The @code{@@refill} command had to be written at the end of every paragraph to cause these formatters to fill them. (Both @TeX{} and @code{makeinfo} have always refilled paragraphs automatically.) Now, all the Info formatters automatically fill and indent those paragraphs that need to be filled and indented.@refill The @code{@@refill} command causes @code{texinfo-format-region} and @code{texinfo-format-buffer} to refill a paragraph in the Info file @emph{after} all the other processing has been done. For this reason, you can not use @code{@@refill} with a paragraph containing either @code{@@*} or @code{@@w@{ @dots{} @}} since the refilling action will override those two commands.@refill The @code{texinfo-format-region} and @code{texinfo-format-buffer} commands now automatically append @code{@@refill} to the end of each paragraph that should be filled. They do not append @code{@@refill} to the ends of paragraphs that contain @code{@@*} or @w{@code{@@w@{ @dots{}@}}} and therefore do not refill or indent them.@refill @end ignore @c These are no longer ``new'', and the explanations @c are all given elsewhere anyway, I think. --karl, 25apr97. @c So ignore the entire appendix. @ignore @c node New Features, Command and Variable Index, Obtaining TeX, Top @c appendix Second Edition Features @tex % Widen the space for the first column so three control-character % strings fit in the first column. Switched back to default .8in % value at end of chapter. \global\tableindent=1.0in @end tex The second edition of the Texinfo manual describes more than 20 new Texinfo mode commands and more than 50 previously undocumented Texinfo @@-commands. This edition is more than twice the length of the first edition.@refill Here is a brief description of the new commands.@refill @c menu * New Texinfo Mode Commands:: The updating commands are especially useful. * New Commands:: Many newly described @@-commands. @c end menu @c node New Texinfo Mode Commands, New Commands, Obtaining TeX, Obtaining TeX @c appendixsec New Texinfo Mode Commands Texinfo mode provides commands and features especially designed for working with Texinfo files. More than 20 new commands have been added, including commands for automatically creating and updating both nodes and menus. This is a tedious task when done by hand.@refill The keybindings are intended to be somewhat mnemonic.@refill @c subheading Update all nodes and menus The @code{texinfo-master-menu} command is the primary command: @table @kbd @item C-c C-u m @itemx M-x texinfo-master-menu Create or update a master menu. With @kbd{C-u} as a prefix argument, first create or update all nodes and regular menus. @end table @c subheading Update Pointers @noindent Create or update `Next', `Previous', and `Up' node pointers.@refill @noindent @xref{Updating Nodes and Menus}. @table @kbd @item C-c C-u C-n @itemx M-x texinfo-update-node Update a node. @item C-c C-u C-e @itemx M-x texinfo-every-node-update Update every node in the buffer. @end table @c subheading Update Menus @noindent Create or update menus.@refill @noindent @xref{Updating Nodes and Menus}. @table @kbd @item C-c C-u C-m @itemx M-x texinfo-make-menu Make or update a menu. @item C-c C-u C-a @itemx M-x texinfo-all-menus-update Make or update all the menus in a buffer. With @kbd{C-u} as a prefix argument, first update all the nodes. @end table @c subheading Insert Title as Description @noindent Insert a node's chapter or section title in the space for the description in a menu entry line; position point so you can edit the insert. (This command works somewhat differently than the other insertion commands, which insert only a predefined string.)@refill @noindent @xref{Inserting, Inserting Frequently Used Commands}. @table @kbd @item C-c C-c C-d Insert title. @end table @c subheading Format for Info @noindent Provide keybindings both for the Info formatting commands that are written in Emacs Lisp and for @code{makeinfo} that is written in C.@refill @noindent @xref{Info Formatting}. @noindent Use the Emacs lisp @code{texinfo-format@dots{}} commands: @table @kbd @item C-c C-e C-r Format the region. @item C-c C-e C-b Format the buffer. @end table @noindent Use @code{makeinfo}: @table @kbd @item C-c C-m C-r Format the region. @item C-c C-m C-b Format the buffer. @item C-c C-m C-l Recenter the @code{makeinfo} output buffer. @item C-c C-m C-k Kill the @code{makeinfo} formatting job. @end table @c subheading Typeset and Print @noindent Typeset and print Texinfo documents from within Emacs. @noindent @xref{Printing}. @table @kbd @item C-c C-t C-b Run @code{texi2dvi} on the buffer. @item C-c C-t C-r Run @TeX{} on the region. @item C-c C-t C-i Run @code{texindex}. @item C-c C-t C-p Print the DVI file. @item C-c C-t C-q Show the print queue. @item C-c C-t C-d Delete a job from the print queue. @item C-c C-t C-k Kill the current @TeX{} formatting job. @item C-c C-t C-x Quit a currently stopped @TeX{} formatting job. @item C-c C-t C-l Recenter the output buffer. @end table @c subheading Other Updating Commands @noindent The ``other updating commands'' do not have standard keybindings because they are used less frequently.@refill @noindent @xref{Other Updating Commands}. @table @kbd @item M-x texinfo-insert-node-lines Insert missing @code{@@node} lines using section titles as node names. @item M-x texinfo-multiple-files-update Update a multi-file document. With a numeric prefix, such as @kbd{C-u 8}, update @strong{every} pointer and menu in @strong{all} the files and then insert a master menu. @item M-x texinfo-indent-menu-description Indent descriptions in menus. @item M-x texinfo-sequential-node-update Insert node pointers in strict sequence. @end table @c no.de New Commands, , New Texinfo Mode Commands, Obtaining TeX @c appendix.sec New Texinfo @@-Commands The second edition of the Texinfo manual describes more than 50 commands that were not described in the first edition. A third or so of these commands existed in Texinfo but were not documented in the manual; the others are new. Here is a listing, with brief descriptions of them:@refill @c subheading Indexing @noindent Create your own index, and merge indices.@refill @noindent @xref{Indices}. @table @kbd @item @@defindex @var{index-name} Define a new index and its indexing command. See also the @code{@@defcodeindex} command. @c written verbosely to avoid overfull hbox @item @@synindex @var{from-index} @var{into-index} Merge the @var{from-index} index into the @var{into-index} index. See also the @code{@@syncodeindex} command. @end table @c subheading Definitions @noindent Describe functions, variables, macros, commands, user options, special forms, and other such artifacts in a uniform format.@refill @noindent @xref{Definition Commands}. @table @kbd @item @@deffn @var{category} @var{name} @var{arguments}@dots{} Format a description for functions, interactive commands, and similar entities. @item @@defvr, @@defop, @dots{} 15 other related commands. @end table @c subheading Glyphs @noindent Indicate the results of evaluation, expansion, printed output, an error message, equivalence of expressions, and the location of point.@refill @noindent @xref{Glyphs}. @table @kbd @item @@equiv@{@} @itemx @equiv{} Equivalence: @item @@error@{@} @itemx @error{} Error message @item @@expansion@{@} @itemx @expansion{} Macro expansion @item @@point@{@} @itemx @point{} Position of point @item @@print@{@} @itemx @print{} Printed output @item @@result@{@} @itemx @result{} Result of an expression @end table @c subheading Page Headings @noindent Customize page headings. @noindent @xref{Headings}. @table @kbd @item @@headings @var{on-off-single-double} Headings on or off, single, or double-sided. @item @@evenfooting [@var{left}] @@| [@var{center}] @@| [@var{right}] Footings for even-numbered (left-hand) pages. @item @@evenheading, @@everyheading, @@oddheading, @dots{} Five other related commands. @item @@thischapter Insert name of chapter and chapter number. @item @@thischaptername, @@thisfile, @@thistitle, @@thispage Related commands. @end table @c subheading Formatting @noindent Format blocks of text. @noindent @xref{Quotations and Examples}, and@* @ref{Lists and Tables, , Making Lists and Tables}. @table @kbd @item @@cartouche Draw rounded box surrounding text (no effect in Info). @item @@enumerate @var{optional-arg} Enumerate a list with letters or numbers. @item @@exdent @var{line-of-text} Remove indentation. @item @@flushleft Left justify. @item @@flushright Right justify. @item @@format Do not narrow nor change font. @item @@ftable @var{formatting-command} @itemx @@vtable @var{formatting-command} Two-column table with indexing. @item @@lisp For an example of Lisp code. @item @@smallexample @itemx @@smalllisp Like @@table and @@lisp, but for (originally) @@smallbook. @end table @c subheading Conditionals @noindent Conditionally format text. @noindent @xref{set clear value, , @code{@@set} @code{@@clear} @code{@@value}}.@refill @table @kbd @item @@set @var{flag} [@var{string}] Set a flag. Optionally, set value of @var{flag} to @var{string}. @item @@clear @var{flag} Clear a flag. @item @@value@{@var{flag}@} Replace with value to which @var{flag} is set. @item @@ifset @var{flag} Format, if @var{flag} is set. @item @@ifclear @var{flag} Ignore, if @var{flag} is set. @end table @c subheading @@heading series for Titles @noindent Produce unnumbered headings that do not appear in a table of contents. @noindent @xref{Structuring}. @table @kbd @item @@heading @var{title} Unnumbered section-like heading not listed in the table of contents of a printed manual. @item @@chapheading, @@majorheading, @@c subheading, @@subsubheading Related commands. @end table @need 1000 @c subheading Font commands @need 1000 @noindent @xref{Smallcaps}, and @* @ref{Fonts}. @table @kbd @item @@r@{@var{text}@} Print in roman font. @item @@sc@{@var{text}@} Print in @sc{small caps} font. @end table @c subheading Miscellaneous @noindent See @ref{title subtitle author, , @code{@@title} @code{@@subtitle} and @code{@@author} Commands},@* see @ref{Customized Highlighting},@* see @ref{Overfull hboxes},@* see @ref{Footnotes},@* see @ref{dmn, , Format a Dimension},@* see @ref{Raise/lower sections, , @code{@@raisesections} and @code{@@lowersections}},@* see @ref{math, , @code{@@math}: Inserting Mathematical Expressions}.@* see @ref{minus, , Inserting a Minus Sign},@* see @ref{paragraphindent, , Paragraph Indenting},@* see @ref{Cross Reference Commands},@* see @ref{title subtitle author, , @code{@@title} @code{@@subtitle} and @code{@@author}}, and@* see @ref{Custom Headings, , How to Make Your Own Headings}. @table @kbd @item @@author @var{author} Typeset author's name. @c @item @@definfoenclose @var{new-command}, @var{before}, @var{after}, @c Define a highlighting command for Info. (Info only.) @item @@finalout Produce cleaner printed output. @item @@footnotestyle @var{end-or-separate} Specify footnote style. @item @@dmn@{@var{dimension}@} Format a dimension. @item @@global@@let@var{new-cmd}=@var{existing-cmd} Define a highlighting command for @TeX{}. (@TeX{} only.) @item @@lowersections Reduce hierarchical level of sectioning commands. @item @@math@{@var{mathematical-expression}@} Format a mathematical expression. @item @@minus@{@} Generate a minus sign. @item @@paragraphindent @var{asis-or-number} Specify paragraph indentation. @item @@raisesections Raise hierarchical level of sectioning commands. @item @@ref@{@var{node-name}, @r{[}@var{entry}@r{]}, @r{[}@var{topic-or-title}@r{]}, @r{[}@var{info-file}@r{]}, @r{[}@var{manual}@r{]}@} Make a reference. In the printed manual, the reference does not start with the word `see'. @item @@title @var{title} Typeset @var{title} in the alternative title page format. @item @@subtitle @var{subtitle} Typeset @var{subtitle} in the alternative title page format. @item @@today@{@} Insert the current date. @end table @tex % Switch width of first column of tables back to default value \global\tableindent=.8in @end tex @end ignore @node Copying This Manual @appendix Copying This Manual @menu * GNU Free Documentation License:: License for copying this manual. @end menu @include fdl.texi @node Command and Variable Index @unnumbered Command and Variable Index This is an alphabetical list of all the @@-commands, assorted Emacs Lisp functions, and several variables. To make the list easier to use, the commands are listed without their preceding @samp{@@}.@refill @printindex fn @node Concept Index @unnumbered Concept Index @printindex cp @bye