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> #include <curl/curl.h> /* * Download two HTTP files! */ int main(void) { CURL *curl; CURL *curl2; CURLcode result = curl_global_init(CURL_GLOBAL_ALL); if(result != CURLE_OK) return (int)result; curl = curl_easy_init(); curl2 = curl_easy_init(); if(curl && curl2) { CURLM *multi; /* set options */ curl_easy_setopt(curl, CURLOPT_URL, "https://www.example.com/"); /* set options */ curl_easy_setopt(curl2, CURLOPT_URL, "http://localhost/"); /* init a multi stack */ multi = curl_multi_init(); if(multi) { int still_running = 1; /* keep number of running handles */ /* add the individual transfers */ curl_multi_add_handle(multi, curl); curl_multi_add_handle(multi, curl2); while(still_running) { CURLMsg *msg; int queued; CURLMcode mresult = curl_multi_perform(multi, &still_running); if(still_running) /* wait for activity, timeout or "nothing" */ mresult = curl_multi_poll(multi, NULL, 0, 1000, NULL); if(mresult) break; do { msg = curl_multi_info_read(multi, &queued); if(msg) { if(msg->msg == CURLMSG_DONE) { /* a transfer ended */ fprintf(stderr, "Transfer completed\n"); } } } while(msg); } curl_multi_remove_handle(multi, curl); curl_multi_remove_handle(multi, curl2); curl_multi_cleanup(multi); } } curl_easy_cleanup(curl); curl_easy_cleanup(curl2); curl_global_cleanup(); return 0; }
Notice
This source code example is simplified and may ignore return
codes and error checks. We do this to highlight the libcurl function calls and
related options and reduce unrelated code.
A real-world application does of course properly check every return value and exit correctly at the first serious error.