function ping($host) {
   $package = "\x08\x00\x19\x2f\x00\x00\x00\x00\x70\x69\x6e\x67";

   /* create the socket, the last '1' denotes ICMP */    
   $socket = socket_create(AF_INET, SOCK_RAW, 1);
   
   /* set socket receive timeout to 1 second */
   socket_set_option($socket, SOL_SOCKET, SO_RCVTIMEO, array("sec" => 1, "usec" => 0));
   
   /* connect to socket */
   socket_connect($socket, $host, null);
   
   /* record start time */
   list($start_usec, $start_sec) = explode(" ", microtime());
   $start_time = ((float) $start_usec + (float) $start_sec);
   
   socket_send($socket, $package, strlen($package), 0);
   
   if(@socket_read($socket, 255)) {
       list($end_usec, $end_sec) = explode(" ", microtime());
       $end_time = ((float) $end_usec + (float) $end_sec);
   
       $total_time = $end_time - $start_time;
       
       return $total_time;
   } else {
       return false;
   }
   
   socket_close($socket);
}

echo ping ("www.google.com");