CMakeLua/Utilities/cmcurl-7.19.0/docs/examples/multi-single.c

   1 /*****************************************************************************
   2  *                                  _   _ ____  _
   3  *  Project                     ___| | | |  _ \| |
   4  *                             / __| | | | |_) | |
   5  *                            | (__| |_| |  _ <| |___
   6  *                             \___|\___/|_| \_\_____|
   7  *
   8  * $Id: multi-single.c,v 1.1.1.1 2008-09-23 16:32:05 hoffman Exp $
   9  *
  10  * This is a very simple example using the multi interface.
  11  */
  12
  13 #include <stdio.h>
  14 #include <string.h>
  15
  16 /* somewhat unix-specific */
  17 #include <sys/time.h>
  18 #include <unistd.h>
  19
  20 /* curl stuff */
  21 #include <curl/curl.h>
  22
  23 /*
  24  * Simply download a HTTP file.
  25  */
  26 int main(int argc, char **argv)
  27 {
  28   CURL *http_handle;
  29   CURLM *multi_handle;
  30
  31   int still_running; /* keep number of running handles */
  32
  33   http_handle = curl_easy_init();
  34
  35   /* set the options (I left out a few, you'll get the point anyway) */
  36   curl_easy_setopt(http_handle, CURLOPT_URL, "http://www.haxx.se/");
  37
  38   /* init a multi stack */
  39   multi_handle = curl_multi_init();
  40
  41   /* add the individual transfers */
  42   curl_multi_add_handle(multi_handle, http_handle);
  43
  44   /* we start some action by calling perform right away */
  45   while(CURLM_CALL_MULTI_PERFORM ==
  46         curl_multi_perform(multi_handle, &still_running));
  47
  48   while(still_running) {
  49     struct timeval timeout;
  50     int rc; /* select() return code */
  51
  52     fd_set fdread;
  53     fd_set fdwrite;
  54     fd_set fdexcep;
  55     int maxfd;
  56
  57     FD_ZERO(&fdread);
  58     FD_ZERO(&fdwrite);
  59     FD_ZERO(&fdexcep);
  60
  61     /* set a suitable timeout to play around with */
  62     timeout.tv_sec = 1;
  63     timeout.tv_usec = 0;
  64
  65     /* get file descriptors from the transfers */
  66     curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
  67
  68     /* In a real-world program you OF COURSE check the return code of the
  69        function calls, *and* you make sure that maxfd is bigger than -1 so
  70        that the call to select() below makes sense! */
  71
  72     rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
  73
  74     switch(rc) {
  75     case -1:
  76       /* select error */
  77       still_running = 0;
  78       printf("select() returns error, this is badness\n");
  79       break;
  80     case 0:
  81     default:
  82       /* timeout or readable/writable sockets */
  83       while(CURLM_CALL_MULTI_PERFORM ==
  84             curl_multi_perform(multi_handle, &still_running));
  85       break;
  86     }
  87   }
  88
  89   curl_multi_cleanup(multi_handle);
  90
  91   curl_easy_cleanup(http_handle);
  92
  93   return 0;
  94 }