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
34static 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
45static 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
51int 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
92    long curl_timeo = -1;
93
94    /* Initialise the file descriptors */
95    FD_ZERO(&fdread);
96    FD_ZERO(&fdwrite);
97    FD_ZERO(&fdexcep);
98
99    /* Set a suitable timeout to play around with */
100    timeout.tv_sec = 1;
101    timeout.tv_usec = 0;
102
103    curl_multi_timeout(mcurl, &curl_timeo);
104    if(curl_timeo >= 0) {
105      timeout.tv_sec = curl_timeo / 1000;
106      if(timeout.tv_sec > 1)
107        timeout.tv_sec = 1;
108      else
109        timeout.tv_usec = (curl_timeo % 1000) * 1000;
110    }
111
112    /* Get file descriptors from the transfers */
113    curl_multi_fdset(mcurl, &fdread, &fdwrite, &fdexcep, &maxfd);
114
115    /* In a real-world program you OF COURSE check the return code of the
116       function calls.  On success, the value of maxfd is guaranteed to be
117       greater or equal than -1.  We call select(maxfd + 1, ...), specially in
118       case of (maxfd == -1), we call select(0, ...), which is basically equal
119       to sleep. */
120    rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
121
122    if(tvdiff(tvnow(), mp_start) > MULTI_PERFORM_HANG_TIMEOUT) {
123      fprintf(stderr,
124              "ABORTING: Since it seems that we would have run forever.\n");
125      break;
126    }
127
128    switch(rc) {
129    case -1:  /* select error */
130      break;
131    case 0:   /* timeout */
132    default:  /* action */
133      curl_multi_perform(mcurl, &still_running);
134      break;
135    }
136  }
137
138  /* Always cleanup */
139  curl_multi_remove_handle(mcurl, curl);
140  curl_multi_cleanup(mcurl);
141  curl_easy_cleanup(curl);
142  curl_global_cleanup();
143
144  return 0;
145}
146