curl/docs/libcurl/opts/CURLOPT_STREAM_DEPENDS.3

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.TH CURLOPT_STREAM_DEPENDS 3 "13 Sep 2015" "libcurl 7.46.0" "curl_easy_setopt options"
.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 will cause this
function to return an error. It must be another easy handle, and it also needs
to be a handle of a transfer that will 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 CURLOPT_STREAM_WEIGHT "(3), " CURLOPT_STREAM_DEPENDS_E "(3), "