Question

I’ve problem with libcurl. I wrote simple program which should post data (fill the form) but program’s not working.
My form:

...
<div><label for="id_person_name">Your name</label> <input type="text" id="id_person_name" name="name" /></div>
            <div></div>

            <div class="clear"></div>
            <div><label for="id_comment">Comment</label><textarea name="comment" id="id_comment" rows="10" cols="60" class="txt"></textarea></div>
...

Program:

#include <curl/curl.h>
#include <iostream>

using namespace std;

int main(){

CURL *curl;
CURLcode res;

curl = curl_easy_init();

if(curl) {
   curl_easy_setopt(curl, CURLOPT_URL, "http://examplesite.com");
   curl_easy_setopt(curl, CURLOPT_POST, 1);
   curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "name=Bjarne&comment=example");
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);

cout << endl;
}
return 0;
}

Of course i tested this code: http://curl.haxx.se/libcurl/c/postit2.html but it’s not working.

Can anyone help me ?

Answer 1

you need to set CURLOPT_URL to address which <form> points, as shown here, for example.

The code from the above link is:

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2015, Daniel Stenberg, <[e-mail]>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/ 
/* <DESC>
 * simple HTTP POST using the easy interface
 * </DESC>
 */ 
#include <stdio.h>
#include <curl/curl.h>

int main(void)
{
  CURL *curl;
  CURLcode res;

  /* In windows, this will init the winsock stuff */ 
  curl_global_init(CURL_GLOBAL_ALL);

  /* get a curl handle */ 
  curl = curl_easy_init();
  if(curl) {
    /* First set the URL that is about to receive our POST. This URL can
       just as well be a https:// URL if that is what should receive the
       data. */ 
    curl_easy_setopt(curl, CURLOPT_URL, "http://postit.example.com/moo.cgi");
    /* Now specify the POST data */ 
    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "name=daniel&project=curl");

    /* Perform the request, res will get the return code */ 
    res = curl_easy_perform(curl);
    /* Check for errors */ 
    if(res != CURLE_OK)
      fprintf(stderr, "curl_easy_perform() failed: %s\n",
              curl_easy_strerror(res));

    /* always cleanup */ 
    curl_easy_cleanup(curl);
  }
  curl_global_cleanup();
  return 0;
}