/*************************************************************************** * _ _ ____ _ * Project ___| | | | _ \| | * / __| | | | |_) | | * | (__| |_| | _ <| |___ * \___|\___/|_| \_\_____| * * Copyright (C) 1998 - 2016, 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.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. * ***************************************************************************/ /* <DESC> * A basic application source code using the multi interface doing two * transfers in parallel. * </DESC> */ #include <stdio.h> #include <string.h> /* somewhat unix-specific */ #include <sys/time.h> #include <unistd.h> /* curl stuff */ #include <curl/curl.h> /* * Download a HTTP file and upload an FTP file simultaneously. */ #define HANDLECOUNT 2 /* Number of simultaneous transfers */ #define HTTP_HANDLE 0 /* Index for the HTTP transfer */ #define FTP_HANDLE 1 /* Index for the FTP transfer */ int main(void) { CURL *handles[HANDLECOUNT]; CURLM *multi_handle; int still_running; /* keep number of running handles */ int i; CURLMsg *msg; /* for picking up messages with the transfer status */ int msgs_left; /* how many messages are left */ /* Allocate one CURL handle per transfer */ for(i=0; i<HANDLECOUNT; i++) handles[i] = curl_easy_init(); /* set the options (I left out a few, you'll get the point anyway) */ curl_easy_setopt(handles[HTTP_HANDLE], CURLOPT_URL, "http://example.com"); curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_URL, "ftp://example.com"); curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_UPLOAD, 1L); /* init a multi stack */ multi_handle = curl_multi_init(); /* add the individual transfers */ for(i=0; i<HANDLECOUNT; i++) curl_multi_add_handle(multi_handle, handles[i]); /* 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 */ CURLMcode mc; /* curl_multi_fdset() 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 */ mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd); if(mc != CURLM_OK) { fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc); break; } /* On success the value of maxfd is guaranteed to be >= -1. We call select(maxfd + 1, ...); specially in case of (maxfd == -1) there are no fds ready yet so we call select(0, ...) --or Sleep() on Windows-- to sleep 100ms, which is the minimum suggested value in the curl_multi_fdset() doc. */ if(maxfd == -1) { #ifdef _WIN32 Sleep(100); rc = 0; #else /* Portable sleep for platforms other than Windows. */ struct timeval wait = { 0, 100 * 1000 }; /* 100ms */ rc = select(0, NULL, NULL, NULL, &wait); #endif } else { /* Note that on some platforms 'timeout' may be modified by select(). If you need access to the original value save a copy beforehand. */ rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout); } switch(rc) { case -1: /* select error */ break; case 0: /* timeout */ default: /* action */ curl_multi_perform(multi_handle, &still_running); break; } } while(still_running); /* See how the transfers went */ while((msg = curl_multi_info_read(multi_handle, &msgs_left))) { if(msg->msg == CURLMSG_DONE) { int idx, found = 0; /* Find out which handle this message is about */ for(idx=0; idx<HANDLECOUNT; idx++) { found = (msg->easy_handle == handles[idx]); if(found) break; } switch(idx) { case HTTP_HANDLE: printf("HTTP transfer completed with status %d\n", msg->data.result); break; case FTP_HANDLE: printf("FTP transfer completed with status %d\n", msg->data.result); break; } } } curl_multi_cleanup(multi_handle); /* Free the CURL handles */ for(i=0; i<HANDLECOUNT; i++) curl_easy_cleanup(handles[i]); return 0; }