CURLMOPT_PIPELINING(3)

1CURLMOPT_PIPELINING(3)     curl_multi_setopt options    CURLMOPT_PIPELINING(3)
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NAME

6       CURLMOPT_PIPELINING - enable HTTP pipelining and multiplexing
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SYNOPSIS

9       #include <curl/curl.h>
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11       CURLMcode  curl_multi_setopt(CURLM  *handle,  CURLMOPT_PIPELINING, long
12       bitmask);
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DESCRIPTION

15       Pass in the bitmask parameter to instruct libcurl to enable HTTP  pipe‐
16       lining and/or HTTP/2 multiplexing for this multi handle.
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18       When  enabled, libcurl will attempt to use those protocol features when
19       doing parallel requests to the same hosts.
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21       For pipelining, this means that if you add a second  request  that  can
22       use  an already existing connection, the second request will be "piped"
23       on the same connection rather than being executed in parallel.
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25       For multiplexing, this means that follow-up requests can re-use an  ex‐
26       isting connection and send the new request multiplexed over that at the
27       same time as other transfers are already using that single connection.
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29       There are several other related options that are interesting  to  tweak
30       and  adjust to alter how libcurl spreads out requests on different con‐
31       nections or not etc.
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33       Before 7.43.0, this option was set to 1 and 0  to  enable  and  disable
34       HTTP/1.1 pipelining.
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36       Starting  in  7.43.0,  bitmask's second bit also has a meaning, and you
37       can ask for pipelining and multiplexing independently of each other  by
38       toggling the correct bits.
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40       CURLPIPE_NOTHING
41       Default, which means doing no attempts at pipelining or multiplexing.
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43       CURLPIPE_HTTP1
44        If  this bit is set, libcurl will try to pipeline HTTP/1.1 requests on
45        connections that are already established and in use to hosts.
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47        This bit is deprecated and has no effect since version 7.62.0.
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49       CURLPIPE_MULTIPLEX
50         If this bit is set, libcurl will try to multiplex  the  new  transfer
51         over an existing connection if possible. This requires HTTP/2.
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DEFAULT

54       Since 7.62.0, CURLPIPE_MULTIPLEX is enabled by default.
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56       Before that, default was CURLPIPE_NOTHING.
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PROTOCOLS

59       HTTP(S)
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EXAMPLE

62       CURLM *m = curl_multi_init();
63       /* try HTTP/2 multiplexing */
64       curl_multi_setopt(m, CURLMOPT_PIPELINING, CURLPIPE_MULTIPLEX);
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AVAILABILITY

67       Added in 7.16.0. Multiplex support bit added in 7.43.0. HTTP/1 Pipelin‐
68       ing support was disabled in 7.62.0.
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RETURN VALUE

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