/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2011, 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 http://curl.haxx.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. * ***************************************************************************/ /* This is a very simple example using the multi interface. */ #include <stdio.h> #include <string.h> /* somewhat unix-specific */ #include <sys/time.h> #include <unistd.h> /* curl stuff */ #include <curl/curl.h> /* * Simply download a HTTP file. */ int main(void) { CURL *http_handle; CURLM *multi_handle; int still_running; /* keep number of running handles */ curl_global_init(CURL_GLOBAL_DEFAULT); http_handle = curl_easy_init(); /* set the options (I left out a few, you'll get the point anyway) */ curl_easy_setopt(http_handle, CURLOPT_URL, "http://www.example.com/"); /* init a multi stack */ multi_handle = curl_multi_init(); /* add the individual transfers */ curl_multi_add_handle(multi_handle, http_handle); /* we start some action by calling perform right away */ curl_multi_perform(multi_handle, &still_running); do { struct timeval timeout; int rc; /* select() return code */ fd_set fdread; fd_set fdwrite; fd_set fdexcep; int maxfd = -1; long curl_timeo = -1; FD_ZERO(&fdread); FD_ZERO(&fdwrite); FD_ZERO(&fdexcep); /* set a suitable timeout to play around with */ timeout.tv_sec = 1; timeout.tv_usec = 0; curl_multi_timeout(multi_handle, &curl_timeo); if(curl_timeo >= 0) { timeout.tv_sec = curl_timeo / 1000; if(timeout.tv_sec > 1) timeout.tv_sec = 1; else timeout.tv_usec = (curl_timeo % 1000) * 1000; } /* get file descriptors from the transfers */ curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd); /* In a real-world program you OF COURSE check the return code of the function calls. On success, the value of maxfd is guaranteed to be greater or equal than -1. We call select(maxfd + 1, ...), specially in case of (maxfd == -1), we call select(0, ...), which is basically equal to sleep. */ rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout); switch(rc) { case -1: /* select error */ still_running = 0; printf("select() returns error, this is badness\n"); break; case 0: default: /* timeout or readable/writable sockets */ curl_multi_perform(multi_handle, &still_running); break; } } while(still_running); curl_multi_remove_handle(multi_handle, http_handle); curl_easy_cleanup(http_handle); curl_multi_cleanup(multi_handle); curl_global_cleanup(); return 0; }