<?php
define('TWITTER_MAX', 140);
define('TWITTER_SPACER', ' ');
function _real_twitter_nodeapi(&$node, $op, $a3, $a4)
{
   if (!($op == 'insert' || $op == 'update'))
      return;
   // only run for published story nodes
   if (!$node->status || ($node->type != 'story'))
      return;

   $username = 'your_username';
   $password = 'your_password';
   $status = url('node/'.$node->nid, NULL, NULL, TRUE);
   if (drupal_strlen($status) < TWITTER_MAX-strlen(TWITTER_SPACER))
   {
      $status = drupal_substr($node->title, 0, TWITTER_MAX-strlen(TWITTER_SPACER)-drupal_strlen($status))
         . TWITTER_SPACER . $status;
   }
   $socket = fsockopen('twitter.com', 80, $errno, $errstr, 20);
   if (!$socket)
   {
      drupal_watchdog(t('Could not ping twitter on insert of node %node',
               array('%node' => $node->nid)));
      return;
   }
   $postdata = 'status='.urlencode($status);
   $out = "POST /statuses/update.xml HTTP/1.0\r\n";
   $out .= "Host: twitter.com\r\n";
   $out .= "Authorization: Basic ".base64_encode($username.':'.$password)."\r\n";
   $out .= "Content-Type: application/x-www-form-urlencoded\r\n";
   $out .= "Content-Length: ".strlen($postdata)."\r\n";
   $out .= "Connection: Close\r\n\r\n";
   $out .= $postdata;

   fwrite($socket, $out);
   fclose($socket);
}