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      1 /***************************************************************************
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      5  *                            | (__| |_| |  _ <| |___
      6  *                             \___|\___/|_| \_\_____|
      7  *
      8  * Copyright (C) 1998 - 2012, Daniel Stenberg, <daniel (at) 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. */
     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 
     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