Daniel Stenberg e694c8284a

docs/libcurl/opts: clarify the return values

Expand a little.

- mention the type name of the return code
- avoid stating which exact return codes that might be returned, as that
  varies over time, builds and conditions
- avoid stating some always return OK
- refer to the manpage documenting all the return codes

Closes #15900

2025-01-02 17:13:33 +01:00

1.9 KiB

Raw Blame History

SPDX-License-Identifier

Title

Section

Source

See-also

Protocol

Added-in

curl

CURLOPT_STREAM_DEPENDS

libcurl

CURLMOPT_PIPELINING (3)

CURLOPT_HTTP_VERSION (3)

CURLOPT_STREAM_DEPENDS_E (3)

CURLOPT_STREAM_WEIGHT (3)

HTTP

7.46.0

NAME

CURLOPT_STREAM_DEPENDS - stream this transfer depends on

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_STREAM_DEPENDS,
                          CURL *dephandle);

DESCRIPTION

Pass a CURL pointer in dephandle 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 CURLOPT_STREAM_DEPENDS_E(3) 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.

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.

DEFAULT

NULL

%PROTOCOLS%

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, curl);

    /* then add both to a multi handle and transfer them */
  }
}

%AVAILABILITY%

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).

1.9 KiB Raw Blame History