1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2012, 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 http://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 /* An example of curl_easy_send() and curl_easy_recv() usage. */
23
24 #include <stdio.h>
25 #include <string.h>
26 #include <curl/curl.h>
27
28 /* Auxiliary function that waits on the socket. */
wait_on_socket(curl_socket_t sockfd,int for_recv,long timeout_ms)29 static int wait_on_socket(curl_socket_t sockfd, int for_recv, long timeout_ms)
30 {
31 struct timeval tv;
32 fd_set infd, outfd, errfd;
33 int res;
34
35 tv.tv_sec = timeout_ms / 1000;
36 tv.tv_usec= (timeout_ms % 1000) * 1000;
37
38 FD_ZERO(&infd);
39 FD_ZERO(&outfd);
40 FD_ZERO(&errfd);
41
42 FD_SET(sockfd, &errfd); /* always check for error */
43
44 if(for_recv)
45 {
46 FD_SET(sockfd, &infd);
47 }
48 else
49 {
50 FD_SET(sockfd, &outfd);
51 }
52
53 /* select() returns the number of signalled sockets or -1 */
54 res = select(sockfd + 1, &infd, &outfd, &errfd, &tv);
55 return res;
56 }
57
main(void)58 int main(void)
59 {
60 CURL *curl;
61 CURLcode res;
62 /* Minimalistic http request */
63 const char *request = "GET / HTTP/1.0\r\nHost: example.com\r\n\r\n";
64 curl_socket_t sockfd; /* socket */
65 long sockextr;
66 size_t iolen;
67 curl_off_t nread;
68
69 curl = curl_easy_init();
70 if(curl) {
71 curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
72 /* Do not do the transfer - only connect to host */
73 curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 1L);
74 res = curl_easy_perform(curl);
75
76 if(CURLE_OK != res)
77 {
78 printf("Error: %s\n", strerror(res));
79 return 1;
80 }
81
82 /* Extract the socket from the curl handle - we'll need it for waiting.
83 * Note that this API takes a pointer to a 'long' while we use
84 * curl_socket_t for sockets otherwise.
85 */
86 res = curl_easy_getinfo(curl, CURLINFO_LASTSOCKET, &sockextr);
87
88 if(CURLE_OK != res)
89 {
90 printf("Error: %s\n", curl_easy_strerror(res));
91 return 1;
92 }
93
94 sockfd = sockextr;
95
96 /* wait for the socket to become ready for sending */
97 if(!wait_on_socket(sockfd, 0, 60000L))
98 {
99 printf("Error: timeout.\n");
100 return 1;
101 }
102
103 puts("Sending request.");
104 /* Send the request. Real applications should check the iolen
105 * to see if all the request has been sent */
106 res = curl_easy_send(curl, request, strlen(request), &iolen);
107
108 if(CURLE_OK != res)
109 {
110 printf("Error: %s\n", curl_easy_strerror(res));
111 return 1;
112 }
113 puts("Reading response.");
114
115 /* read the response */
116 for(;;)
117 {
118 char buf[1024];
119
120 wait_on_socket(sockfd, 1, 60000L);
121 res = curl_easy_recv(curl, buf, 1024, &iolen);
122
123 if(CURLE_OK != res)
124 break;
125
126 nread = (curl_off_t)iolen;
127
128 printf("Received %" CURL_FORMAT_CURL_OFF_T " bytes.\n", nread);
129 }
130
131 /* always cleanup */
132 curl_easy_cleanup(curl);
133 }
134 return 0;
135 }
136