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 */
main(void)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 }
112