Return to multi-app.c CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / curl / docs / examples

curl

    1: /***************************************************************************
    2:  *                                  _   _ ____  _
    3:  *  Project                     ___| | | |  _ \| |
    4:  *                             / __| | | | |_) | |
    5:  *                            | (__| |_| |  _ <| |___
    6:  *                             \___|\___/|_| \_\_____|
    7:  *
    8:  * Copyright (C) 1998 - 2019, Daniel Stenberg, <daniel@haxx.se>, et al.
    9:  *
   10:  * This software is licensed as described in the file COPYING, which
   11:  * you should have received as part of this distribution. The terms
   12:  * are also available at https://curl.haxx.se/docs/copyright.html.
   13:  *
   14:  * You may opt to use, copy, modify, merge, publish, distribute and/or sell
   15:  * copies of the Software, and permit persons to whom the Software is
   16:  * furnished to do so, under the terms of the COPYING file.
   17:  *
   18:  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
   19:  * KIND, either express or implied.
   20:  *
   21:  ***************************************************************************/
   22: /* <DESC>
   23:  * A basic application source code using the multi interface doing two
   24:  * transfers in parallel.
   25:  * </DESC>
   26:  */
   27: 
   28: #include <stdio.h>
   29: #include <string.h>
   30: 
   31: /* somewhat unix-specific */
   32: #include <sys/time.h>
   33: #include <unistd.h>
   34: 
   35: /* curl stuff */
   36: #include <curl/curl.h>
   37: 
   38: /*
   39:  * Download a HTTP file and upload an FTP file simultaneously.
   40:  */
   41: 
   42: #define HANDLECOUNT 2   /* Number of simultaneous transfers */
   43: #define HTTP_HANDLE 0   /* Index for the HTTP transfer */
   44: #define FTP_HANDLE 1    /* Index for the FTP transfer */
   45: 
   46: int main(void)
   47: {
   48:   CURL *handles[HANDLECOUNT];
   49:   CURLM *multi_handle;
   50: 
   51:   int still_running = 0; /* keep number of running handles */
   52:   int i;
   53: 
   54:   CURLMsg *msg; /* for picking up messages with the transfer status */
   55:   int msgs_left; /* how many messages are left */
   56: 
   57:   /* Allocate one CURL handle per transfer */
   58:   for(i = 0; i<HANDLECOUNT; i++)
   59:     handles[i] = curl_easy_init();
   60: 
   61:   /* set the options (I left out a few, you'll get the point anyway) */
   62:   curl_easy_setopt(handles[HTTP_HANDLE], CURLOPT_URL, "https://example.com");
   63: 
   64:   curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_URL, "ftp://example.com");
   65:   curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_UPLOAD, 1L);
   66: 
   67:   /* init a multi stack */
   68:   multi_handle = curl_multi_init();
   69: 
   70:   /* add the individual transfers */
   71:   for(i = 0; i<HANDLECOUNT; i++)
   72:     curl_multi_add_handle(multi_handle, handles[i]);
   73: 
   74:   /* we start some action by calling perform right away */
   75:   curl_multi_perform(multi_handle, &still_running);
   76: 
   77:   while(still_running) {
   78:     struct timeval timeout;
   79:     int rc; /* select() return code */
   80:     CURLMcode mc; /* curl_multi_fdset() return code */
   81: 
   82:     fd_set fdread;
   83:     fd_set fdwrite;
   84:     fd_set fdexcep;
   85:     int maxfd = -1;
   86: 
   87:     long curl_timeo = -1;
   88: 
   89:     FD_ZERO(&fdread);
   90:     FD_ZERO(&fdwrite);
   91:     FD_ZERO(&fdexcep);
   92: 
   93:     /* set a suitable timeout to play around with */
   94:     timeout.tv_sec = 1;
   95:     timeout.tv_usec = 0;
   96: 
   97:     curl_multi_timeout(multi_handle, &curl_timeo);
   98:     if(curl_timeo >= 0) {
   99:       timeout.tv_sec = curl_timeo / 1000;
  100:       if(timeout.tv_sec > 1)
  101:         timeout.tv_sec = 1;
  102:       else
  103:         timeout.tv_usec = (curl_timeo % 1000) * 1000;
  104:     }
  105: 
  106:     /* get file descriptors from the transfers */
  107:     mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
  108: 
  109:     if(mc != CURLM_OK) {
  110:       fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
  111:       break;
  112:     }
  113: 
  114:     /* On success the value of maxfd is guaranteed to be >= -1. We call
  115:        select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
  116:        no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
  117:        to sleep 100ms, which is the minimum suggested value in the
  118:        curl_multi_fdset() doc. */
  119: 
  120:     if(maxfd == -1) {
  121: #ifdef _WIN32
  122:       Sleep(100);
  123:       rc = 0;
  124: #else
  125:       /* Portable sleep for platforms other than Windows. */
  126:       struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
  127:       rc = select(0, NULL, NULL, NULL, &wait);
  128: #endif
  129:     }
  130:     else {
  131:       /* Note that on some platforms 'timeout' may be modified by select().
  132:          If you need access to the original value save a copy beforehand. */
  133:       rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
  134:     }
  135: 
  136:     switch(rc) {
  137:     case -1:
  138:       /* select error */
  139:       break;
  140:     case 0: /* timeout */
  141:     default: /* action */
  142:       curl_multi_perform(multi_handle, &still_running);
  143:       break;
  144:     }
  145:   }
  146: 
  147:   /* See how the transfers went */
  148:   while((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
  149:     if(msg->msg == CURLMSG_DONE) {
  150:       int idx;
  151: 
  152:       /* Find out which handle this message is about */
  153:       for(idx = 0; idx<HANDLECOUNT; idx++) {
  154:         int found = (msg->easy_handle == handles[idx]);
  155:         if(found)
  156:           break;
  157:       }
  158: 
  159:       switch(idx) {
  160:       case HTTP_HANDLE:
  161:         printf("HTTP transfer completed with status %d\n", msg->data.result);
  162:         break;
  163:       case FTP_HANDLE:
  164:         printf("FTP transfer completed with status %d\n", msg->data.result);
  165:         break;
  166:       }
  167:     }
  168:   }
  169: 
  170:   curl_multi_cleanup(multi_handle);
  171: 
  172:   /* Free the CURL handles */
  173:   for(i = 0; i<HANDLECOUNT; i++)
  174:     curl_easy_cleanup(handles[i]);
  175: 
  176:   return 0;
  177: }