CURLMOPT_PIPELINING - Man Page

#include <curl/curl.h>

CURLMcode curl_multi_setopt(CURLM *handle, CURLMOPT_PIPELINING, long bitmask);

Pass in the correct value in the bitmask parameter to instruct libcurl to enable multiplexing for this multi handle.

With multiplexing enabled, libcurl attempts to do multiple transfers over the same connection when doing parallel transfers to the same hosts.

CURLPIPE_NOTHING (0)

Default, which means doing no attempts at multiplexing.

CURLPIPE_HTTP1 (1)

This bit is deprecated and has no effect since version 7.62.0.

CURLPIPE_MULTIPLEX (2)

If this bit is set, libcurl tries to multiplex the new transfer over an existing connection if possible. This requires HTTP/2 or HTTP/3.

CURLPIPE_MULTIPLEX

This functionality affects http only

int main(void)
{
  CURLM *m = curl_multi_init();
  /* try HTTP/2 multiplexing */
  curl_multi_setopt(m, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
}

The multiplex support bit was added in 7.43.0. HTTP/1 Pipelining support was disabled in 7.62.0.

Since 7.62.0, CURLPIPE_MULTIPLEX is enabled by default.

Before that, default was CURLPIPE_NOTHING.

Added in curl 7.16.0

Returns CURLM_OK if the option is supported, and CURLM_UNKNOWN_OPTION if not.

CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE(3), CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE(3), CURLMOPT_MAXCONNECTS(3), CURLMOPT_MAX_HOST_CONNECTIONS(3), CURLMOPT_MAX_PIPELINE_LENGTH(3), CURLMOPT_PIPELINING_SITE_BL(3)

CURLMOPT_CHUNK_LENGTH_PENALTY_SIZE(3), CURLMOPT_CONTENT_LENGTH_PENALTY_SIZE(3), CURLMOPT_MAX_PIPELINE_LENGTH(3), CURLMOPT_MAX_TOTAL_CONNECTIONS(3), CURLMOPT_PIPELINING_SERVER_BL(3), CURLMOPT_PIPELINING_SITE_BL(3), CURLMOPT_PUSHDATA(3), CURLMOPT_PUSHFUNCTION(3), curl_multi_setopt(3), CURLOPT_PIPEWAIT(3), CURLOPT_STREAM_DEPENDS(3), CURLOPT_STREAM_DEPENDS_E(3), CURLOPT_STREAM_WEIGHT(3), libcurl-symbols(3).