1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2017, 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 multipart formpost without blocking
24 * </DESC>
25 */
26
27#include <stdio.h>
28#include <string.h>
29#include <sys/time.h>
30
31#include <curl/curl.h>
32
33int main(void)
34{
35  CURL *curl;
36
37  CURLM *multi_handle;
38  int still_running;
39
40  struct curl_httppost *formpost = NULL;
41  struct curl_httppost *lastptr = NULL;
42  struct curl_slist *headerlist = NULL;
43  static const char buf[] = "Expect:";
44
45  /* Fill in the file upload field. This makes libcurl load data from
46     the given file name when curl_easy_perform() is called. */
47  curl_formadd(&formpost,
48               &lastptr,
49               CURLFORM_COPYNAME, "sendfile",
50               CURLFORM_FILE, "postit2.c",
51               CURLFORM_END);
52
53  /* Fill in the filename field */
54  curl_formadd(&formpost,
55               &lastptr,
56               CURLFORM_COPYNAME, "filename",
57               CURLFORM_COPYCONTENTS, "postit2.c",
58               CURLFORM_END);
59
60  /* Fill in the submit field too, even if this is rarely needed */
61  curl_formadd(&formpost,
62               &lastptr,
63               CURLFORM_COPYNAME, "submit",
64               CURLFORM_COPYCONTENTS, "send",
65               CURLFORM_END);
66
67  curl = curl_easy_init();
68  multi_handle = curl_multi_init();
69
70  /* initialize custom header list (stating that Expect: 100-continue is not
71     wanted */
72  headerlist = curl_slist_append(headerlist, buf);
73  if(curl && multi_handle) {
74
75    /* what URL that receives this POST */
76    curl_easy_setopt(curl, CURLOPT_URL, "http://www.example.com/upload.cgi");
77    curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
78
79    curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headerlist);
80    curl_easy_setopt(curl, CURLOPT_HTTPPOST, formpost);
81
82    curl_multi_add_handle(multi_handle, curl);
83
84    curl_multi_perform(multi_handle, &still_running);
85
86    do {
87      struct timeval timeout;
88      int rc; /* select() return code */
89      CURLMcode mc; /* curl_multi_fdset() return code */
90
91      fd_set fdread;
92      fd_set fdwrite;
93      fd_set fdexcep;
94      int maxfd = -1;
95
96      long curl_timeo = -1;
97
98      FD_ZERO(&fdread);
99      FD_ZERO(&fdwrite);
100      FD_ZERO(&fdexcep);
101
102      /* set a suitable timeout to play around with */
103      timeout.tv_sec = 1;
104      timeout.tv_usec = 0;
105
106      curl_multi_timeout(multi_handle, &curl_timeo);
107      if(curl_timeo >= 0) {
108        timeout.tv_sec = curl_timeo / 1000;
109        if(timeout.tv_sec > 1)
110          timeout.tv_sec = 1;
111        else
112          timeout.tv_usec = (curl_timeo % 1000) * 1000;
113      }
114
115      /* get file descriptors from the transfers */
116      mc = curl_multi_fdset(multi_handle, &fdread, &fdwrite, &fdexcep, &maxfd);
117
118      if(mc != CURLM_OK) {
119        fprintf(stderr, "curl_multi_fdset() failed, code %d.\n", mc);
120        break;
121      }
122
123      /* On success the value of maxfd is guaranteed to be >= -1. We call
124         select(maxfd + 1, ...); specially in case of (maxfd == -1) there are
125         no fds ready yet so we call select(0, ...) --or Sleep() on Windows--
126         to sleep 100ms, which is the minimum suggested value in the
127         curl_multi_fdset() doc. */
128
129      if(maxfd == -1) {
130#ifdef _WIN32
131        Sleep(100);
132        rc = 0;
133#else
134        /* Portable sleep for platforms other than Windows. */
135        struct timeval wait = { 0, 100 * 1000 }; /* 100ms */
136        rc = select(0, NULL, NULL, NULL, &wait);
137#endif
138      }
139      else {
140        /* Note that on some platforms 'timeout' may be modified by select().
141           If you need access to the original value save a copy beforehand. */
142        rc = select(maxfd + 1, &fdread, &fdwrite, &fdexcep, &timeout);
143      }
144
145      switch(rc) {
146      case -1:
147        /* select error */
148        break;
149      case 0:
150      default:
151        /* timeout or readable/writable sockets */
152        printf("perform!\n");
153        curl_multi_perform(multi_handle, &still_running);
154        printf("running: %d!\n", still_running);
155        break;
156      }
157    } while(still_running);
158
159    curl_multi_cleanup(multi_handle);
160
161    /* always cleanup */
162    curl_easy_cleanup(curl);
163
164    /* then cleanup the formpost chain */
165    curl_formfree(formpost);
166
167    /* free slist */
168    curl_slist_free_all(headerlist);
169  }
170  return 0;
171}
172