sendrecv.c

/*****************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * An example of curl_easy_send() and curl_easy_recv() usage.
 *
 * $Id: sendrecv.c,v 1.3 2009-11-02 21:20:45 bagder Exp $
 */ 
 
#include <stdio.h>
#include <string.h>
#include <curl/curl.h>
 
/* Auxiliary function that waits on the socket. */ 
static int wait_on_socket(int sockfd, int for_recv, long timeout_ms)
{
  struct timeval tv;
  fd_set infd, outfd, errfd;
  int res;
 
  tv.tv_sec = timeout_ms / 1000;
  tv.tv_usec= (timeout_ms % 1000) * 1000;
 
  FD_ZERO(&infd);
  FD_ZERO(&outfd);
  FD_ZERO(&errfd);
 
  FD_SET(sockfd, &errfd); /* always check for error */ 
 
  if(for_recv)
  {
    FD_SET(sockfd, &infd);
  }
  else
  {
    FD_SET(sockfd, &outfd);
  }
 
  /* select() returns the number of signalled sockets or -1 */ 
  res = select(sockfd + 1, &infd, &outfd, &errfd, &tv);
  return res;
}
 
int main(void)
{
  CURL *curl;
  CURLcode res;
  /* Minimalistic http request */ 
  const char *request = "GET / HTTP/1.0\r\nHost: curl.haxx.se\r\n\r\n";
  int sockfd; /* socket */ 
  size_t iolen;
 
  curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "curl.haxx.se");
    /* Do not do the transfer - only connect to host */ 
    curl_easy_setopt(curl, CURLOPT_CONNECT_ONLY, 1L);
    res = curl_easy_perform(curl);
 
    if(CURLE_OK != res)
    {
      printf("Error: %s\n", strerror(res));
      return 1;
    }
 
    /* Extract the socket from the curl handle - we'll need it
     * for waiting */ 
    res = curl_easy_getinfo(curl, CURLINFO_LASTSOCKET, &sockfd);
 
    if(CURLE_OK != res)
    {
      printf("Error: %s\n", curl_easy_strerror(res));
      return 1;
    }
 
    /* wait for the socket to become ready for sending */ 
    if(!wait_on_socket(sockfd, 0, 60000L))
    {
      printf("Error: timeout.\n");
      return 1;
    }
 
    puts("Sending request.");
    /* Send the request. Real applications should check the iolen
     * to see if all the request has been sent */ 
    res = curl_easy_send(curl, request, strlen(request), &iolen);
 
    if(CURLE_OK != res)
    {
      printf("Error: %s\n", curl_easy_strerror(res));
      return 1;
    }
    puts("Reading response.");
 
    /* read the response */ 
    for(;;)
    {
      char buf[1024];
 
      wait_on_socket(sockfd, 1, 60000L);
      res = curl_easy_recv(curl, buf, 1024, &iolen);
 
      if(CURLE_OK != res)
        break;
 
      printf("Received %u bytes.\n", iolen);
    }
 
    /* always cleanup */ 
    curl_easy_cleanup(curl);
  }
  return 0;
}

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