1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2011, 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 http://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#include <stdio.h>
23#include <string.h>
24
25/* somewhat unix-specific */
26#include <sys/time.h>
27#include <unistd.h>
28
29/* curl stuff */
30#include <curl/curl.h>
31
32/*
33 * Simply download two HTTP files!
34 */
35int main(void)
36{
37  CURL *http_handle;
38  CURL *http_handle2;
39  CURLM *multi_handle;
40
41  int still_running; /* keep number of running handles */
42
43  http_handle = curl_easy_init();
44  http_handle2 = curl_easy_init();
45
46  /* set options */
47  curl_easy_setopt(http_handle, CURLOPT_URL, "http://www.example.com/");
48
49  /* set options */
50  curl_easy_setopt(http_handle2, CURLOPT_URL, "http://localhost/");
51
52  /* init a multi stack */
53  multi_handle = curl_multi_init();
54
55  /* add the individual transfers */
56  curl_multi_add_handle(multi_handle, http_handle);
57  curl_multi_add_handle(multi_handle, http_handle2);
58
59  /* we start some action by calling perform right away */
60  curl_multi_perform(multi_handle, &still_running);
61
62  while(still_running) {
63    struct timeval timeout;
64    int rc; /* select() return code */
65
66    fd_set fdread;
67    fd_set fdwrite;
68    fd_set fdexcep;
69    int maxfd = -1;
70
71    long curl_timeo = -1;
72
73    FD_ZERO(&fdread);
74    FD_ZERO(&fdwrite);
75    FD_ZERO(&fdexcep);
76
77    /* set a suitable timeout to play around with */
78    timeout.tv_sec = 1;
79    timeout.tv_usec = 0;
80
81    curl_multi_timeout(multi_handle, &curl_timeo);
82    if(curl_timeo >= 0) {
83      timeout.tv_sec = curl_timeo / 1000;
84      if(timeout.tv_sec > 1)
85        timeout.tv_sec = 1;
86      else
87        timeout.tv_usec = (curl_timeo % 1000) * 1000;
88    }
89
90    /* get file descriptors from the transfers */
91    curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
92
93    /* In a real-world program you OF COURSE check the return code of the
94       function calls.  On success, the value of maxfd is guaranteed to be
95       greater or equal than -1.  We call select(maxfd + 1, ...), specially in
96       case of (maxfd == -1), we call select(0, ...), which is basically equal
97       to sleep. */
98
99    rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
100
101    switch(rc) {
102    case -1:
103      /* select error */
104      break;
105    case 0:
106    default:
107      /* timeout or readable/writable sockets */
108      curl_multi_perform(multi_handle, &still_running);
109      break;
110    }
111  }
112
113  curl_multi_cleanup(multi_handle);
114
115  curl_easy_cleanup(http_handle);
116  curl_easy_cleanup(http_handle2);
117
118  return 0;
119}
120