// ============================================================================
// C servlet sample for the G-WAN Web Application Server (http://trustleap.ch/)
// ----------------------------------------------------------------------------
// curl.c: get an URL, just like G-WAN's xbuf_frurl()
//
//         (curl does much more than this, supporting DICT, FILE, FTP, FTPS, 
//          GOPHER, HTTP, HTTPS, IMAP, IMAPS, LDAP, LDAPS, POP3, POP3S, RTMP,
//          RTSP, SCP, SFTP, SMTP, SMTPS, TELNET, TFTP, HTTP POST, HTTP PUT, 
//          FTP uploading, etc.)
//
// Notes: for this example to work, you obviously need libcurl but you will
//        also need libcurl4-gnutls-dev or libcurl4-openssl-dev for the headers
//
//        If you get a warning like "_curl_easy_setopt_err_write_callback 
//        declared with attribute warning" then it comes from the source 
//        code of libcurl, which did not finalize its 64-bit port.
// ----------------------------------------------------------------------------
// the full path is needed because this library pre-installed on Linux is not
// properly configured (it is not declared as a library, and there is no 
// default link to libcurl.so)
//
#pragma link "curl"

#include "gwan.h"
#include <curl/curl.h>
// ----------------------------------------------------------------------------
size_t writer(char *data, size_t size, size_t nmemb, xbuf_t *xbuf)
{
   if(!xbuf)
      return 0;
      
   int len = size * nmemb;
   if(len > 0)
      xbuf_ncat(xbuf, data, len);
   
   return len;
}
// ----------------------------------------------------------------------------
CURLcode http_get(char *url, xbuf_t *xbuf)
{
   CURL *curl = curl_easy_init();
   if(!curl)
      return 0;

   curl_easy_setopt(curl, CURLOPT_URL, url);
   curl_easy_setopt(curl, CURLOPT_HEADER, 1);
   curl_easy_setopt(curl, CURLOPT_HTTP_TRANSFER_DECODING, 0);
   curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1);
   curl_easy_setopt(curl, CURLOPT_MAXREDIRS, 50L);
   curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 1);
   curl_easy_setopt(curl, CURLOPT_USERAGENT, "G-WAN");
   curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writer);
   curl_easy_setopt(curl, CURLOPT_WRITEDATA, xbuf);
   CURLcode result = curl_easy_perform(curl);
   curl_easy_cleanup(curl);
   return result;
}
// ----------------------------------------------------------------------------
int main(int argc, char *argv[])
{
   char *url = "curl.haxx.se/libcurl/c/";
   xbuf_t *reply = get_reply(argv), xbuf;

   xbuf_init(&xbuf);
   
   if(http_get(url, &xbuf) != CURLE_OK)
      xbuf_cat(reply, "Server or resource not available");
   else
      xbuf_ncat(reply, xbuf.ptr, xbuf.len);
      
   xbuf_free(&xbuf);   
   return HTTP_200_OK;
}
// ============================================================================
// End of Source Code
// ============================================================================