regex - Match URL pattern in PHP using a regular expression

Question

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

I would like the match four types of URL:

1. http://example.com
2. https://example.com
3. www.example.com
4. example.com

preg_replace('@(https?://([-w.]+)+(:d+)?(/([w/_.]*(?S+)?)?)?)@',
             '<a href="$1">$1</a>', $subject);

This expression matches only first two types of URL.

If I use this expression for matching a URL pattern, '@(www?([-w.]+)+(:d+)?(/([w/_.]*(?S+)?)?)?)@', it only matches the third type of URL pattern.

How can I match all four typeS of URL patternS with a single regular expression?

Answer 1

A complete working example using Nev Stokes' given link:

public function clickableUrls($html){
    return $result = preg_replace(
        '%(([w-]+://?|www[.])[^s()<>]+(?:([wd]+)|([^[:punct:]s]|/)))%s',
        '<a href="$1">$1</a>',
        $html
    );
}