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.
SEE ALSO
CURLOPT_SSL_FALSESTART(3),
libcurl 7.81.0 November 26, 2021 CURLOPT_TCP_FASTOPEN(3)
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