1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 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.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 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24/* <DESC>
25 * A basic application source code using the multi interface doing two
26 * transfers in parallel without curl_multi_wait/poll.
27 * </DESC>
28 */
29
30#include <stdio.h>
31#include <string.h>
32
33/* somewhat unix-specific */
34#include <sys/time.h>
35#include <unistd.h>
36
37/* curl stuff */
38#include <curl/curl.h>
39
40/*
41 * Download an HTTP file and upload an FTP file simultaneously.
42 */
43
44#define HANDLECOUNT 2   /* Number of simultaneous transfers */
45#define HTTP_HANDLE 0   /* Index for the HTTP transfer */
46#define FTP_HANDLE 1    /* Index for the FTP transfer */
47
48int main(void)
49{
50  CURL *handles[HANDLECOUNT];
51  CURLM *multi_handle;
52
53  int still_running = 0; /* keep number of running handles */
54  int i;
55
56  CURLMsg *msg; /* for picking up messages with the transfer status */
57  int msgs_left; /* how many messages are left */
58
59  /* Allocate one CURL handle per transfer */
60  for(i = 0; i<HANDLECOUNT; i++)
61    handles[i] = curl_easy_init();
62
63  /* set the options (I left out a few, you will get the point anyway) */
64  curl_easy_setopt(handles[HTTP_HANDLE], CURLOPT_URL, "https://example.com");
65
66  curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_URL, "ftp://example.com");
67  curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_UPLOAD, 1L);
68
69  /* init a multi stack */
70  multi_handle = curl_multi_init();
71
72  /* add the individual transfers */
73  for(i = 0; i<HANDLECOUNT; i++)
74    curl_multi_add_handle(multi_handle, handles[i]);
75
76  /* we start some action by calling perform right away */
77  curl_multi_perform(multi_handle, &still_running);
78
79  while(still_running) {
80    struct timeval timeout;
81    int rc; /* select() return code */
82    CURLMcode mc; /* curl_multi_fdset() return code */
83
84    fd_set fdread;
85    fd_set fdwrite;
86    fd_set fdexcep;
87    int maxfd = -1;
88
89    long curl_timeo = -1;
90
91    FD_ZERO(&fdread);
92    FD_ZERO(&fdwrite);
93    FD_ZERO(&fdexcep);
94
95    /* set a suitable timeout to play around with */
96    timeout.tv_sec = 1;
97    timeout.tv_usec = 0;
98
99    curl_multi_timeout(multi_handle, &curl_timeo);
100    if(curl_timeo >= 0) {
101      timeout.tv_sec = curl_timeo / 1000;
102      if(timeout.tv_sec > 1)
103        timeout.tv_sec = 1;
104      else
105        timeout.tv_usec = (int)(curl_timeo % 1000) * 1000;
106    }
107
108    /* get file descriptors from the transfers */
109    mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
110
111    if(mc != CURLM_OK) {
112      fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
113      break;
114    }
115
116    /* On success the value of maxfd is guaranteed to be >= -1. We call
117       select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
118       no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
119       to sleep 100ms, which is the minimum suggested value in the
120       curl_multi_fdset() doc. */
121
122    if(maxfd == -1) {
123#ifdef _WIN32
124      Sleep(100);
125      rc = 0;
126#else
127      /* Portable sleep for platforms other than Windows. */
128      struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
129      rc = select(0, NULL, NULL, NULL, &wait);
130#endif
131    }
132    else {
133      /* Note that on some platforms 'timeout' may be modified by select().
134         If you need access to the original value save a copy beforehand. */
135      rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
136    }
137
138    switch(rc) {
139    case -1:
140      /* select error */
141      break;
142    case 0: /* timeout */
143    default: /* action */
144      curl_multi_perform(multi_handle, &still_running);
145      break;
146    }
147  }
148
149  /* See how the transfers went */
150  while((msg = curl_multi_info_read(multi_handle, &msgs_left))) {
151    if(msg->msg == CURLMSG_DONE) {
152      int idx;
153
154      /* Find out which handle this message is about */
155      for(idx = 0; idx<HANDLECOUNT; idx++) {
156        int found = (msg->easy_handle == handles[idx]);
157        if(found)
158          break;
159      }
160
161      switch(idx) {
162      case HTTP_HANDLE:
163        printf("HTTP transfer completed with status %d\n", msg->data.result);
164        break;
165      case FTP_HANDLE:
166        printf("FTP transfer completed with status %d\n", msg->data.result);
167        break;
168      }
169    }
170  }
171
172  curl_multi_cleanup(multi_handle);
173
174  /* Free the CURL handles */
175  for(i = 0; i<HANDLECOUNT; i++)
176    curl_easy_cleanup(handles[i]);
177
178  return 0;
179}
180