xref: /curl/docs/examples/multi-app.c (revision 53b4dfe4)
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.
27  * </DESC>
28  */
29 
30 #include <stdio.h>
31 #include <string.h>
32 
33 /* curl stuff */
34 #include <curl/curl.h>
35 
36 /*
37  * Download an HTTP file and upload an FTP file simultaneously.
38  */
39 
40 #define HANDLECOUNT 2   /* Number of simultaneous transfers */
41 #define HTTP_HANDLE 0   /* Index for the HTTP transfer */
42 #define FTP_HANDLE 1    /* Index for the FTP transfer */
43 
main(void)44 int main(void)
45 {
46   CURL *handles[HANDLECOUNT];
47   CURLM *multi_handle;
48 
49   int still_running = 1; /* keep number of running handles */
50   int i;
51 
52   CURLMsg *msg; /* for picking up messages with the transfer status */
53   int msgs_left; /* how many messages are left */
54 
55   /* Allocate one CURL handle per transfer */
56   for(i = 0; i<HANDLECOUNT; i++)
57     handles[i] = curl_easy_init();
58 
59   /* set the options (I left out a few, you get the point anyway) */
60   curl_easy_setopt(handles[HTTP_HANDLE], CURLOPT_URL, "https://example.com");
61 
62   curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_URL, "ftp://example.com");
63   curl_easy_setopt(handles[FTP_HANDLE], CURLOPT_UPLOAD, 1L);
64 
65   /* init a multi stack */
66   multi_handle = curl_multi_init();
67 
68   /* add the individual transfers */
69   for(i = 0; i<HANDLECOUNT; i++)
70     curl_multi_add_handle(multi_handle, handles[i]);
71 
72   while(still_running) {
73     CURLMcode mc = curl_multi_perform(multi_handle, &still_running);
74 
75     if(still_running)
76       /* wait for activity, timeout or "nothing" */
77       mc = curl_multi_poll(multi_handle, NULL, 0, 1000, NULL);
78 
79     if(mc)
80       break;
81   }
82   /* See how the transfers went */
83   /* !checksrc! disable EQUALSNULL 1 */
84   while((msg = curl_multi_info_read(multi_handle, &msgs_left)) != NULL) {
85     if(msg->msg == CURLMSG_DONE) {
86       int idx;
87 
88       /* Find out which handle this message is about */
89       for(idx = 0; idx<HANDLECOUNT; idx++) {
90         int found = (msg->easy_handle == handles[idx]);
91         if(found)
92           break;
93       }
94 
95       switch(idx) {
96       case HTTP_HANDLE:
97         printf("HTTP transfer completed with status %d\n", msg->data.result);
98         break;
99       case FTP_HANDLE:
100         printf("FTP transfer completed with status %d\n", msg->data.result);
101         break;
102       }
103     }
104   }
105 
106   /* remove the transfers and cleanup the handles */
107   for(i = 0; i<HANDLECOUNT; i++) {
108     curl_multi_remove_handle(multi_handle, handles[i]);
109     curl_easy_cleanup(handles[i]);
110   }
111 
112   curl_multi_cleanup(multi_handle);
113 
114   return 0;
115 }
116