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Updated: Wednesday, July 27, 2022
 
 

CURLOPT_TCP_FASTOPEN (3)

Name

CURLOPT_TCP_FASTOPEN - TCP Fast Open

Synopsis

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_FASTOPEN, long enable);

Description

CURLOPT_TCP_FASTOPEN(3)    curl_easy_setopt options    CURLOPT_TCP_FASTOPEN(3)



NAME
       CURLOPT_TCP_FASTOPEN - TCP Fast Open

SYNOPSIS
       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_FASTOPEN, long enable);

DESCRIPTION
       Pass a long as parameter set to 1L to enable or 0 to disable.

       TCP  Fast  Open (RFC7413) is a mechanism that allows data to be carried
       in the SYN and SYN-ACK packets and consumed by the receiving end during
       the initial connection handshake, saving up to one full round-trip time
       (RTT).

DEFAULT
       0

PROTOCOLS
       All

EXAMPLE
       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
         curl_easy_setopt(curl, CURLOPT_TCP_FASTOPEN, 1L);
         curl_easy_perform(curl);
       }

AVAILABILITY
       Added in 7.49.0. This option is currently only supported on  Linux  and
       OS X El Capitan.

RETURN VALUE
       Returns  CURLE_OK  if  fast  open is supported by the operating system,
       otherwise returns CURLE_NOT_BUILT_IN.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+------------------+
       |ATTRIBUTE TYPE | ATTRIBUTE VALUE  |
       +---------------+------------------+
       |Availability   | web/curl         |
       +---------------+------------------+
       |Stability      | Uncommitted      |
       +---------------+------------------+

SEE ALSO
       CURLOPT_SSL_FALSESTART(3),



NOTES
       Source code for open source software components in Oracle  Solaris  can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source      was      downloaded       from        https://curl.se/down-
       load/curl-7.83.1.tar.bz2.

       Further information about this software can be found on the open source
       community website at http://curl.haxx.se/.



libcurl 7.83.1                 November 26, 2021       CURLOPT_TCP_FASTOPEN(3)