.\" **************************************************************************
.\" *                                  _   _ ____  _
.\" *  Project                     ___| | | |  _ \| |
.\" *                             / __| | | | |_) | |
.\" *                            | (__| |_| |  _ <| |___
.\" *                             \___|\___/|_| \_\_____|
.\" *
.\" * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
.\" *
.\" * This software is licensed as described in the file COPYING, which
.\" * you should have received as part of this distribution. The terms
.\" * are also available at https://curl.se/docs/copyright.html.
.\" *
.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
.\" * copies of the Software, and permit persons to whom the Software is
.\" * furnished to do so, under the terms of the COPYING file.
.\" *
.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
.\" * KIND, either express or implied.
.\" *
.\" * SPDX-License-Identifier: curl
.\" *
.\" **************************************************************************
.\"
.TH CURLOPT_STREAM_DEPENDS 3 "September 26, 2023" "ibcurl 8.4.0" libcurl

.SH NAME
CURLOPT_STREAM_DEPENDS \- stream this transfer depends on
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STREAM_DEPENDS,
                          CURL *dephandle);
.fi
.SH DESCRIPTION
Pass a CURL * pointer in \fIdephandle\fP to identify the stream within the
same connection that this stream is depending upon. This option clears the
exclusive bit and is mutually exclusive to the
\fICURLOPT_STREAM_DEPENDS_E(3)\fP option.

The spec says "Including a dependency expresses a preference to allocate
resources to the identified stream rather than to the dependent stream."

This option can be set during transfer.

\fIdephandle\fP must not be the same as \fIhandle\fP, that makes this function
return an error. It must be another easy handle, and it also needs to be a
handle of a transfer that is about to be sent over the same HTTP/2 connection
for this option to have an actual effect.
.SH DEFAULT
NULL
.SH PROTOCOLS
HTTP/2
.SH EXAMPLE
.nf
CURL *curl = curl_easy_init();
CURL *curl2 = curl_easy_init(); /* a second handle */
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/one");

  /* the second depends on the first */
  curl_easy_setopt(curl2, CURLOPT_URL, "https://example.com/two");
  curl_easy_setopt(curl2, CURLOPT_STREAM_DEPENDS, curl);

  /* then add both to a multi handle and transfer them! */
}
.fi
.SH AVAILABILITY
Added in 7.46.0
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH "SEE ALSO"
.BR CURLMOPT_PIPELINING (3),
.BR CURLOPT_HTTP_VERSION (3),
.BR CURLOPT_STREAM_DEPENDS_E (3),
.BR CURLOPT_STREAM_WEIGHT (3)
