1 /***************************************************************************
3 * Project ___| | | | _ \| |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
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.
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.
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
21 ***************************************************************************/
23 * An example of curl_easy_send() and curl_easy_recv() usage.
29 #include <curl/curl.h>
31 /* Auxiliary function that waits on the socket. */
32 static int wait_on_socket(curl_socket_t sockfd, int for_recv, long timeout_ms)
35 fd_set infd, outfd, errfd;
38 tv.tv_sec = timeout_ms / 1000;
39 tv.tv_usec= (timeout_ms % 1000) * 1000;
45 FD_SET(sockfd, &errfd); /* always check for error */
48 FD_SET(sockfd, &infd);
51 FD_SET(sockfd, &outfd);
54 /* select() returns the number of signalled sockets or -1 */
55 res = select(sockfd + 1, &infd, &outfd, &errfd, &tv);
63 /* Minimalistic http request */
64 const char *request = "GET / HTTP/1.0\r\nHost: example.com\r\n\r\n";
65 size_t request_len = strlen(request);
67 size_t nsent_total = 0;
69 /* A general note of caution here: if you're using curl_easy_recv() or
70 curl_easy_send() to implement HTTP or _any_ other protocol libcurl
71 supports "natively", you're doing it wrong and you should stop.
73 This example uses HTTP only to show how to use this API, it does not
74 suggest that writing an application doing this is sensible.
77 curl = curl_easy_init();
79 curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
80 /* Do not do the transfer - only connect to host */
81 curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 1L);
82 res = curl_easy_perform(curl);
85 printf("Error: %s\n", curl_easy_strerror(res));
89 /* Extract the socket from the curl handle - we'll need it for waiting. */
90 res = curl_easy_getinfo(curl, CURLINFO_ACTIVESOCKET, &sockfd);
93 printf("Error: %s\n", curl_easy_strerror(res));
97 printf("Sending request.\n");
100 /* Warning: This example program may loop indefinitely.
101 * A production-quality program must define a timeout and exit this loop
102 * as soon as the timeout has expired. */
106 res = curl_easy_send(curl, request + nsent_total,
107 request_len - nsent_total, &nsent);
108 nsent_total += nsent;
110 if(res == CURLE_AGAIN && !wait_on_socket(sockfd, 0, 60000L)) {
111 printf("Error: timeout.\n");
114 } while(res == CURLE_AGAIN);
116 if(res != CURLE_OK) {
117 printf("Error: %s\n", curl_easy_strerror(res));
121 printf("Sent %" CURL_FORMAT_CURL_OFF_T " bytes.\n",
124 } while(nsent_total < request_len);
126 printf("Reading response.\n");
129 /* Warning: This example program may loop indefinitely (see above). */
134 res = curl_easy_recv(curl, buf, sizeof(buf), &nread);
136 if(res == CURLE_AGAIN && !wait_on_socket(sockfd, 1, 60000L)) {
137 printf("Error: timeout.\n");
140 } while(res == CURLE_AGAIN);
142 if(res != CURLE_OK) {
143 printf("Error: %s\n", curl_easy_strerror(res));
148 /* end of the response */
152 printf("Received %" CURL_FORMAT_CURL_OFF_T " bytes.\n",
157 curl_easy_cleanup(curl);