1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2014, 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 <curl/curl.h>
24
25 /* This is a simple example showing how to fetch mail using libcurl's IMAP
26 * capabilities. It builds on the imap-fetch.c example to demonstrate how to
27 * use libcurl's multi interface.
28 *
29 * Note that this example requires libcurl 7.30.0 or above.
30 */
31
32 #define MULTI_PERFORM_HANG_TIMEOUT 60 * 1000
33
tvnow(void)34 static struct timeval tvnow(void)
35 {
36 struct timeval now;
37
38 /* time() returns the value of time in seconds since the epoch */
39 now.tv_sec = (long)time(NULL);
40 now.tv_usec = 0;
41
42 return now;
43 }
44
tvdiff(struct timeval newer,struct timeval older)45 static long tvdiff(struct timeval newer, struct timeval older)
46 {
47 return (newer.tv_sec - older.tv_sec) * 1000 +
48 (newer.tv_usec - older.tv_usec) / 1000;
49 }
50
main(void)51 int main(void)
52 {
53 CURL *curl;
54 CURLM *mcurl;
55 int still_running = 1;
56 struct timeval mp_start;
57
58 curl_global_init(CURL_GLOBAL_DEFAULT);
59
60 curl = curl_easy_init();
61 if(!curl)
62 return 1;
63
64 mcurl = curl_multi_init();
65 if(!mcurl)
66 return 2;
67
68 /* Set username and password */
69 curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
70 curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
71
72 /* This will fetch message 1 from the user's inbox */
73 curl_easy_setopt(curl, CURLOPT_URL, "imap://imap.example.com/INBOX/;UID=1");
74
75 /* Tell the multi stack about our easy handle */
76 curl_multi_add_handle(mcurl, curl);
77
78 /* Record the start time which we can use later */
79 mp_start = tvnow();
80
81 /* We start some action by calling perform right away */
82 curl_multi_perform(mcurl, &still_running);
83
84 while(still_running) {
85 struct timeval timeout;
86 fd_set fdread;
87 fd_set fdwrite;
88 fd_set fdexcep;
89 int maxfd = -1;
90 int rc;
91 CURLMcode mc; /* curl_multi_fdset() return code */
92
93 long curl_timeo = -1;
94
95 /* Initialise the file descriptors */
96 FD_ZERO(&fdread);
97 FD_ZERO(&fdwrite);
98 FD_ZERO(&fdexcep);
99
100 /* Set a suitable timeout to play around with */
101 timeout.tv_sec = 1;
102 timeout.tv_usec = 0;
103
104 curl_multi_timeout(mcurl, &curl_timeo);
105 if(curl_timeo >= 0) {
106 timeout.tv_sec = curl_timeo / 1000;
107 if(timeout.tv_sec > 1)
108 timeout.tv_sec = 1;
109 else
110 timeout.tv_usec = (curl_timeo % 1000) * 1000;
111 }
112
113 /* get file descriptors from the transfers */
114 mc = curl_multi_fdset(mcurl, &fdread, &fdwrite, &fdexcep, &maxfd);
115
116 if(mc != CURLM_OK)
117 {
118 fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
119 break;
120 }
121
122 /* On success the value of maxfd is guaranteed to be >= -1. We call
123 select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
124 no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
125 to sleep 100ms, which is the minimum suggested value in the
126 curl_multi_fdset() doc. */
127
128 if(maxfd == -1) {
129 #ifdef _WIN32
130 Sleep(100);
131 rc = 0;
132 #else
133 /* Portable sleep for platforms other than Windows. */
134 struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
135 rc = select(0, NULL, NULL, NULL, &wait);
136 #endif
137 }
138 else {
139 /* Note that on some platforms 'timeout' may be modified by select().
140 If you need access to the original value save a copy beforehand. */
141 rc = select(maxfd+1, &fdread, &fdwrite, &fdexcep, &timeout);
142 }
143
144 if(tvdiff(tvnow(), mp_start) > MULTI_PERFORM_HANG_TIMEOUT) {
145 fprintf(stderr,
146 "ABORTING: Since it seems that we would have run forever.\n");
147 break;
148 }
149
150 switch(rc) {
151 case -1: /* select error */
152 break;
153 case 0: /* timeout */
154 default: /* action */
155 curl_multi_perform(mcurl, &still_running);
156 break;
157 }
158 }
159
160 /* Always cleanup */
161 curl_multi_remove_handle(mcurl, curl);
162 curl_multi_cleanup(mcurl);
163 curl_easy_cleanup(curl);
164 curl_global_cleanup();
165
166 return 0;
167 }
168