CURLOPT_STREAM_DEPENDS_E(3) Library Functions Manual
NAME
CURLOPT_STREAM_DEPENDS_E - stream this transfer depends on exclusively
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STREAM_DEPENDS_E,
CURL *dephandle);
DESCRIPTION
Pass a CURL pointer in dephandle to identify the stream within the same
connection that this stream is depending upon exclusively. That means
it depends on it and sets the Exclusive bit.
The spec says "Including a dependency expresses a preference to
allocate resources to the identified stream rather than to the
dependent stream."
Setting a dependency with the exclusive flag for a reprioritized stream
causes all the dependencies of the new parent stream to become
dependent on the reprioritized stream.
This option can be set during transfer.
dephandle must not be the same as handle, 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.
Since version 8.21.0 setting this option no longer has an effect.
HTTP/2 stream dependencies were introduced in RFC 7540 and then later
deprecated in RFC 9113.
DEFAULT
NULL
PROTOCOLS
This functionality affects http only
EXAMPLE
int main(void)
{
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_E, curl);
/* then add both to a multi handle and transfer them */
}
}
DEPRECATED
Deprecated since 8.21.0.
AVAILABILITY
Added in curl 7.46.0
RETURN VALUE
curl_easy_setopt(3) returns a CURLcode indicating success or error.
CURLE_OK (0) means everything was OK, non-zero means an error occurred,
see libcurl-errors(3).
SEE ALSO
CURLMOPT_PIPELINING(3), CURLOPT_HTTP_VERSION(3),
CURLOPT_STREAM_DEPENDS(3), CURLOPT_STREAM_WEIGHT(3)
libcurl 2026-07-05 CURLOPT_STREAM_DEPENDS_E(3)
curl 8.21.0 - Generated Mon Jul 6 10:19:25 CDT 2026