Tribblix: manual page: CURLOPT

CURLOPT_PIPEWAIT(3) Introduction to Library Functions CURLOPT_PIPEWAIT(3)

NAME

CURLOPT_PIPEWAIT - wait for multiplexing

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PIPEWAIT, long wait);

DESCRIPTION

Set wait to 1L to tell libcurl to prefer to wait for a connection to
confirm or deny that it can do multiplexing before continuing.

When about to perform a new transfer that allows multiplexing,
libcurl checks for existing connections to use. If no such connection
exists it immediately continues and creates a fresh new connection to
use.

By setting this option to 1 - and having CURLMOPT_PIPELINING(3)
enabled for the multi handle this transfer is associated with -
libcurl instead waits for the connection to reveal if it is possible
to multiplex on before it continues. This enables libcurl to much
better keep the number of connections to a minimum when using
multiplexing protocols.

With this option set, libcurl prefers to wait and reuse an existing
connection for multiplexing rather than the opposite: prefer to open
a new connection rather than waiting.

The waiting time is as long as it takes for the connection to get up
and for libcurl to get the necessary response back that informs it
about its protocol and support level.

DEFAULT

0 (off)

PROTOCOLS

This functionality affects http only

EXAMPLE

int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
curl_easy_setopt(curl, CURLOPT_PIPEWAIT, 1L);

/* now add this easy handle to the multi handle */
}
}

AVAILABILITY

Added in curl 7.43.0

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).