<?php
function remote_file_size ($url) 
{
   $head = "";
   $url_p = parse_url($url);
   $host = $url_p["host"];
   $path = $url_p["path"];

   $fp = fsockopen($host, 80, $errno, $errstr, 20);
   if(!$fp) 
   { return false; } 
   else 
   {
       fputs($fp, "HEAD ".$url." HTTP/1.1\r\n");
       fputs($fp, "HOST: dummy\r\n");
       fputs($fp, "Connection: close\r\n\r\n");
       $headers = "";
       while (!feof($fp)) {
           $headers .= fgets ($fp, 128);
       }
   }
   fclose ($fp);
   $return = false;
   $arr_headers = explode("\n", $headers);
   foreach($arr_headers as $header) {
       $s = "Content-Length: ";
       if(substr(strtolower ($header), 0, strlen($s)) == strtolower($s)) {
           $return = substr($header, strlen($s));
           break;
       }
   } 
   return $return;
}

print ("Google logo is " . remote_file_size ("http://www.google.it/intl/it_it/images/logo.gif") . " bytes!");
?>