Return to multi-single.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 - 2018, 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:  * using the multi interface to do a single download
   24:  * </DESC>
   25:  */
   26: 
   27: #include <stdio.h>
   28: #include <string.h>
   29: 
   30: /* somewhat unix-specific */
   31: #include <sys/time.h>
   32: #include <unistd.h>
   33: 
   34: /* curl stuff */
   35: #include <curl/curl.h>
   36: 
   37: #ifdef _WIN32
   38: #define WAITMS(x) Sleep(x)
   39: #else
   40: /* Portable sleep for platforms other than Windows. */
   41: #define WAITMS(x)                               \
   42:   struct timeval wait = { 0, (x) * 1000 };      \
   43:   (void)select(0, NULL, NULL, NULL, &wait);
   44: #endif
   45: 
   46: /*
   47:  * Simply download a HTTP file.
   48:  */
   49: int main(void)
   50: {
   51:   CURL *http_handle;
   52:   CURLM *multi_handle;
   53: 
   54:   int still_running = 0; /* keep number of running handles */
   55:   int repeats = 0;
   56: 
   57:   curl_global_init(CURL_GLOBAL_DEFAULT);
   58: 
   59:   http_handle = curl_easy_init();
   60: 
   61:   /* set the options (I left out a few, you'll get the point anyway) */
   62:   curl_easy_setopt(http_handle, CURLOPT_URL, "https://www.example.com/");
   63: 
   64:   /* init a multi stack */
   65:   multi_handle = curl_multi_init();
   66: 
   67:   /* add the individual transfers */
   68:   curl_multi_add_handle(multi_handle, http_handle);
   69: 
   70:   /* we start some action by calling perform right away */
   71:   curl_multi_perform(multi_handle, &still_running);
   72: 
   73:   while(still_running) {
   74:     CURLMcode mc; /* curl_multi_wait() return code */
   75:     int numfds;
   76: 
   77:     /* wait for activity, timeout or "nothing" */
   78:     mc = curl_multi_wait(multi_handle, NULL, 0, 1000, &numfds);
   79: 
   80:     if(mc != CURLM_OK) {
   81:       fprintf(stderr, "curl_multi_wait() failed, code %d.\n", mc);
   82:       break;
   83:     }
   84: 
   85:     /* 'numfds' being zero means either a timeout or no file descriptors to
   86:        wait for. Try timeout on first occurrence, then assume no file
   87:        descriptors and no file descriptors to wait for means wait for 100
   88:        milliseconds. */
   89: 
   90:     if(!numfds) {
   91:       repeats++; /* count number of repeated zero numfds */
   92:       if(repeats > 1) {
   93:         WAITMS(100); /* sleep 100 milliseconds */
   94:       }
   95:     }
   96:     else
   97:       repeats = 0;
   98: 
   99:     curl_multi_perform(multi_handle, &still_running);
  100:   }
  101: 
  102:   curl_multi_remove_handle(multi_handle, http_handle);
  103: 
  104:   curl_easy_cleanup(http_handle);
  105: 
  106:   curl_multi_cleanup(multi_handle);
  107: 
  108:   curl_global_cleanup();
  109: 
  110:   return 0;
  111: }