Slugify a string

slug.php

<?php

/**
 * Convert a human-readable string into a slug
 *
 * 'Sample input string!' gets converted to 'sample-input-string'
 *
 * @param string Source string
 * @return string Slug
 * @author Cake Development Corporation (http://cakedc.com)
 */
function convertToSlug($string) {
	$str = mb_strtolower($string);
	$str = preg_replace('/\xE3\x80\x80/', ' ', $str);
	$str = preg_replace('[\'s ]', 's ', $str);
	$str = str_replace('-', ' ', $str);
	$str = preg_replace( '#[:\#\*"()~$^{}`@+=;,<>!&%\.\]\/\'\\\\|\[]#', "\x20", $str );
	$str = str_replace('?', '', $str);
	$str = trim($str);
	$str = preg_replace('#\x20+#', '-', $str);
	return $str;
}