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| .TH CURLOPT_TCP_FASTOPEN 3 "November 04, 2020" "libcurl 7.78.0" "curl_easy_setopt options" |
| |
| .SH NAME |
| CURLOPT_TCP_FASTOPEN \- enable TCP Fast Open |
| .SH SYNOPSIS |
| #include <curl/curl.h> |
| |
| CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TCP_FASTOPEN, long enable); |
| .SH 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). |
| .SH DEFAULT |
| 0 |
| .SH PROTOCOLS |
| All |
| .SH EXAMPLE |
| .nf |
| 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); |
| } |
| .fi |
| .SH AVAILABILITY |
| Added in 7.49.0. This option is currently only supported on Linux and OS X |
| El Capitan. |
| .SH RETURN VALUE |
| Returns CURLE_OK if fast open is supported by the operating system, otherwise |
| returns CURLE_NOT_BUILT_IN. |
