multi-double.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> * multi interface code doing two parallel HTTP transfers * </DESC> */ #include <stdio.h> #include <string.h> /* curl stuff */ #include <curl/curl.h> /* * Simply download two HTTP files! */ int main(void) { CURL *http_handle; CURL *http_handle2; CURLM *multi_handle; int still_running = 1; /* keep number of running handles */ http_handle = curl_easy_init(); http_handle2 = curl_easy_init(); /* set options */ curl_easy_setopt(http_handle, CURLOPT_URL, "https://www.example.com/"); /* set options */ curl_easy_setopt(http_handle2, CURLOPT_URL, "http://localhost/"); /* init a multi stack */ multi_handle = curl_multi_init(); /* add the individual transfers */ curl_multi_add_handle(multi_handle, http_handle); curl_multi_add_handle(multi_handle, http_handle2); while(still_running) { CURLMsg *msg; int queued; CURLMcode mc = curl_multi_perform(multi_handle, &still_running); if(still_running) /* wait for activity, timeout or "nothing" */ mc = curl_multi_poll(multi_handle, NULL, 0, 1000, NULL); if(mc) break; do { msg = curl_multi_info_read(multi_handle, &queued); if(msg) { if(msg->msg == CURLMSG_DONE) { /* a transfer ended */ fprintf(stderr, "Transfer completed\n"); } } } while(msg); } curl_multi_remove_handle(multi_handle, http_handle); curl_multi_remove_handle(multi_handle, http_handle2); curl_multi_cleanup(multi_handle); curl_easy_cleanup(http_handle); curl_easy_cleanup(http_handle2); return 0; }
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.