Convert urls to links

gistfile1.php

function url_to_link($text)
{
	$text = preg_replace("@\b(https?://)?(([0-9a-zA-Z_!~*'().&=+$%-]+:)?[0-9a-zA-Z_!~*'().&=+$%-]+\@)?(([0-9]{1,3}\.){3}[0-9]{1,3}|([0-9a-zA-Z_!~*'()-]+\.)*([0-9a-zA-Z][0-9a-zA-Z-]{0,61})?[0-9a-zA-Z]\.[a-zA-Z]{2,6})(:[0-9]{1,4})?((/[0-9a-zA-Z_!~*'().;?:\@&=+$,%#-]+)*/?)@", '<a href="\0" target="_blank">\0</a>', $text);
	$text = preg_replace("/href=\"([0-9a-zA-Z_\-]+\.)/U", 'href="http://$1', $text);
	
	return $text;
}