Generate a Google SiteMap with PHP

<?php
	// Sets the file header to show this is an XML file
	header("Content-type: text/xml");
	
	// The xml header is written this way to avoid the <? tags being seen as code
	// by PHP (a problem if short_open_tag == 1)
	echo('<?xml version="1.0" encoding="UTF-8"?>');
	
	// Set this to true to ignore all files beginning with .
	$respectUnixHidden = true;
	// Modify this to ignore specific files, delimited by ';'
	$filesToIgnore = 'sitemap.php;sitemap.pl;error_log;temp.php';
	// Modify this to ignore all files with specific file extensions, 
	// delimited by ';'
	$extensionsToIgnore = 'xml;html;shtml;inc;css;txt';
	// This is added in front of all the found filenames to produce URLs instead
	// of local filenames. For example, if $rootUrl is http://www.google.com, 
	// index.htm will become http://www.google.org.uk/index.htm
	$rootUrl = 'http://www.freetools.org.uk/';
	
	// An array containing the files to be ignored
	$ignoreFiles = explode(';', $filesToIgnore);
	// An array containing the extensons to be ignored
	$ignoreExtensions = explode(';', $extensionsToIgnore);
	echo('<urlset xmlns="http://www.google.com/schemas/sitemap/0.9">');
	
	// Opens the directory the file is stored in and checks it is open
	if ($localDir = opendir('.'))
	{
		// Iterates through each file in the local directory
		while (false !== ($file = readdir($localDir)))
		{
			// Extracts the extension
			$extension = end(explode('.', $file));
			// Checks the filename and extension against the ignore lists
			if (!is_dir($file) and !(in_array($file, $ignoreFiles)) 
			                   and !(in_array($extension, $ignoreExtensions))
							   and !($respectUnixHidden == true and $file[0] == '.'))
			{
				echo('<url>');
				echo('<loc>');
				// Echoes the URL of the file by combining the filename and $rootUrl
				echo("{$rootUrl}{$file}");
				echo('</loc>');
				echo('<lastmod>');
				// Echoes the date the file was last modified in YYY-MM-DD form
				echo(date('Y-m-d', filemtime($file)));
				echo('</lastmod>');
				echo('</url>');
			}
		}
	}
?>
</urlset>