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23 .TH CURLOPT_TCP_FASTOPEN 3 "May 15, 2017" "libcurl 7.59.0" "curl_easy_setopt options"
26 CURLOPT_TCP_FASTOPEN \- enable TCP Fast Open
28 #include <curl/curl.h>
30 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_FASTOPEN, long enable);
32 Pass a long as parameter set to 1L to enable or 0 to disable.
34 TCP Fast Open (RFC7413) is a mechanism that allows data to be carried in the
35 SYN and SYN-ACK packets and consumed by the receiving end during the initial
36 connection handshake, saving up to one full round-trip time (RTT).
43 CURL *curl = curl_easy_init();
45 curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
46 curl_easy_setopt(curl, CURLOPT_TCP_FASTOPEN, 1L);
47 curl_easy_perform(curl);
51 Added in 7.49.0. This option is currently only supported on Linux and OS X
54 Returns CURLE_OK if fast open is supported by the operating system, otherwise
55 returns CURLE_NOT_BUILT_IN.