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 * Download many files in parallel, in the same thread.
26 * </DESC>
27 */
28
29#include <errno.h>
30#include <stdlib.h>
31#include <string.h>
32#ifndef _WIN32
33#  include <unistd.h>
34#endif
35#include <curl/curl.h>
36
37static const char *urls[] = {
38  "https://www.microsoft.com",
39  "https://opensource.org",
40  "https://www.google.com",
41  "https://www.yahoo.com",
42  "https://www.ibm.com",
43  "https://www.mysql.com",
44  "https://www.oracle.com",
45  "https://www.ripe.net",
46  "https://www.iana.org",
47  "https://www.amazon.com",
48  "https://www.netcraft.com",
49  "https://www.heise.de",
50  "https://www.chip.de",
51  "https://www.ca.com",
52  "https://www.cnet.com",
53  "https://www.mozilla.org",
54  "https://www.cnn.com",
55  "https://www.wikipedia.org",
56  "https://www.dell.com",
57  "https://www.hp.com",
58  "https://www.cert.org",
59  "https://www.mit.edu",
60  "https://www.nist.gov",
61  "https://www.ebay.com",
62  "https://www.playstation.com",
63  "https://www.uefa.com",
64  "https://www.ieee.org",
65  "https://www.apple.com",
66  "https://www.symantec.com",
67  "https://www.zdnet.com",
68  "https://www.fujitsu.com/global/",
69  "https://www.supermicro.com",
70  "https://www.hotmail.com",
71  "https://www.ietf.org",
72  "https://www.bbc.co.uk",
73  "https://news.google.com",
74  "https://www.foxnews.com",
75  "https://www.msn.com",
76  "https://www.wired.com",
77  "https://www.sky.com",
78  "https://www.usatoday.com",
79  "https://www.cbs.com",
80  "https://www.nbc.com/",
81  "https://slashdot.org",
82  "https://www.informationweek.com",
83  "https://apache.org",
84  "https://www.un.org",
85};
86
87#define MAX_PARALLEL 10 /* number of simultaneous transfers */
88#define NUM_URLS sizeof(urls)/sizeof(char *)
89
90static size_t write_cb(char *data, size_t n, size_t l, void *userp)
91{
92  /* take care of the data here, ignored in this example */
93  (void)data;
94  (void)userp;
95  return n*l;
96}
97
98static void add_transfer(CURLM *cm, unsigned int i, int *left)
99{
100  CURL *eh = curl_easy_init();
101  curl_easy_setopt(eh, CURLOPT_WRITEFUNCTION, write_cb);
102  curl_easy_setopt(eh, CURLOPT_URL, urls[i]);
103  curl_easy_setopt(eh, CURLOPT_PRIVATE, urls[i]);
104  curl_multi_add_handle(cm, eh);
105  (*left)++;
106}
107
108int main(void)
109{
110  CURLM *cm;
111  CURLMsg *msg;
112  unsigned int transfers = 0;
113  int msgs_left = -1;
114  int left = 0;
115
116  curl_global_init(CURL_GLOBAL_ALL);
117  cm = curl_multi_init();
118
119  /* Limit the amount of simultaneous connections curl should allow: */
120  curl_multi_setopt(cm, CURLMOPT_MAXCONNECTS, (long)MAX_PARALLEL);
121
122  for(transfers = 0; transfers < MAX_PARALLEL && transfers < NUM_URLS;
123      transfers++)
124    add_transfer(cm, transfers, &left);
125
126  do {
127    int still_alive = 1;
128    curl_multi_perform(cm, &still_alive);
129
130    while((msg = curl_multi_info_read(cm, &msgs_left))) {
131      if(msg->msg == CURLMSG_DONE) {
132        char *url;
133        CURL *e = msg->easy_handle;
134        curl_easy_getinfo(msg->easy_handle, CURLINFO_PRIVATE, &url);
135        fprintf(stderr, "R: %d - %s <%s>\n",
136                msg->data.result, curl_easy_strerror(msg->data.result), url);
137        curl_multi_remove_handle(cm, e);
138        curl_easy_cleanup(e);
139        left--;
140      }
141      else {
142        fprintf(stderr, "E: CURLMsg (%d)\n", msg->msg);
143      }
144      if(transfers < NUM_URLS)
145        add_transfer(cm, transfers++, &left);
146    }
147    if(left)
148      curl_multi_wait(cm, NULL, 0, 1000, NULL);
149
150  } while(left);
151
152  curl_multi_cleanup(cm);
153  curl_global_cleanup();
154
155  return EXIT_SUCCESS;
156}
157