Simplest way to parse a title from an HTML file using PHP functions only, no extra classes

So far I've been trying to get a simple way to stract a title from an HTML page.

This simple:

$url = "http://localhost";

Use any function to extract the title tag using only PHP functions or regular expressions, I do not want to use any external classes such as simple_html_dom or Zend_Dom... I want to do it the simple way with PHP only... can anyone post a sample code to simply extract the title tag from localhost?

I've tried using DOMdocument() class, simple_xml_parse(), and none of them with success

I tried like this:

<?php $dom = new DOMdocument(); 
$dom->loadhtml('pag.html'); 
$items = $dom->getElementsByTagName('title');
foreach ($items as $title) { echo "title"; }