CURLOPT_TCP_FASTOPEN(3)

CURLOPT_TCP_FASTOPEN(3curl_easy_setopt optionCURLOPT_TCP_FASTOPEN(3)

NAME

     CURLOPT_TCP_FASTOPEN - enable 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  dis-
     able.

     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, "http://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.

libcurl 7.58.0      Last change: May 15, 2017                   1