match url pattern in php using regular expression

Question

I want to match a url link in wall post and replace this link with anchor tag, for this I use the regular expression below.

I would like the match 4 types of url:

Answer 1

This works great for me - including mailto check:

function LinkIt($text)
{
    $t = preg_replace("/(\b(?:(?:http(s)?|ftp):\/\/|(www\.)))([-a-züöäß0-9+&@#\/%?=~_|!:,.;]*[-a-z0-9+&@#\/%=~_|])/im", '$1$4', $text);
    return preg_replace("/([\w+\.\-]+@[\w+\-]+\.[a-zA-Z]{2,4})/im", strtolower('$1'), $t);
}