keepalive.c
/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. * * This software is licensed as described in the file COPYING, which * you should have received as part of this distribution. The terms * are also available at https://curl.se/docs/copyright.html. * * You may opt to use, copy, modify, merge, publish, distribute and/or sell * copies of the Software, and permit persons to whom the Software is * furnished to do so, under the terms of the COPYING file. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * * SPDX-License-Identifier: curl * ***************************************************************************/ /* <DESC> * Use the TCP keep-alive options * </DESC> */ #include <stdio.h> #include <curl/curl.h> int main(void) { CURL *curl; CURLcode res = CURLE_OK; curl = curl_easy_init(); if(curl) { /* enable TCP keep-alive for this transfer */ curl_easy_setopt(curl, CURLOPT_TCP_KEEPALIVE, 1L); /* keep-alive idle time to 120 seconds */ curl_easy_setopt(curl, CURLOPT_TCP_KEEPIDLE, 120L); /* interval time between keep-alive probes: 60 seconds */ curl_easy_setopt(curl, CURLOPT_TCP_KEEPINTVL, 60L); /* maximum number of keep-alive probes: 3 */ curl_easy_setopt(curl, CURLOPT_TCP_KEEPCNT, 3L); curl_easy_setopt(curl, CURLOPT_URL, "https://curl.se/"); res = curl_easy_perform(curl); curl_easy_cleanup(curl); } return (int)res; }
Notice
This source code example is simplified and ignores return
codes and error checks to a large extent. We do this to highlight the libcurl
function calls and related options and reduce unrelated code.
A real-world application will of course properly check every return value and exit correctly at the first serious error.