PHP: Make Clickable

php-make-clickable.php

<?php
/**
 * Supports normal, ftp, file and email URL’s as well as subdomains. 
 * Also it doesn’t mess with HTML a tags that already exist in the string.
 * 
 * @param  String  $text  Contens that needs to be parsed through
 * @return String         String
 * 
 */

function make_clickable($text){
    return preg_replace('@(?<![.*">])\b(?:(?:https?|ftp|file)://|[a-z]\.)[-A-Z0-9+&#/%=~_|$?!:,.]*[A-Z0-9+&#/%=~_|$]@i', '<a href="\0">\0</a>', $text);
}