Detecte links

Jeg har denne funktion der automatisk laver links klikbare.

function url2link($txt, $class)

{

    $username = "[a-z0-9_\-]+";

    $password = "[a-z0-9_\-!#]+";

    $host = "[a-z0-9\-]+\.[a-z0-9\-\.]+";

    $port = "\d{1,5}";

    $path = "\/[a-z0-9\/\_\-\.\(\)\%]*";

    $querystr = "\?[a-z0-9&=\-\.%\(\)]+";

    $proto = "(https?|ftp):\/\/";

    $url = "$host(:$port)?($path($querystr)?)?";

    $protodomain = "/$proto(($username(:$password)?@)?$url)/i";

    $domain = "/(^| )(www\.$url)/im";

    $protomail = "/mailto:($username@$host)/i";

    $mail = "/(^| )($username@$host)/im";

    $replacements = array(

            $protodomain => "<a href=\"\\0\" target=\"_blank\" class=\"$class\">\\2</a>"

            ,$domain => "\\1<a href=\"http://\\2\" target=\"_blank\" class=\"$class\">\\2</a>"

            ,$protomail => "<a href=\"\\0\" class=\"$class\">\\1</a>"

            ,$mail => "\\1<a href=\"mailto:\\2\" class=\"$class\">\\2</a>"

        );

    return preg_replace( array_keys( $replacements ), array_values( $replacements ), $txt );

}

Problemet er, at følgende link deles op fordi der er / og _ i urlen.

Kan det rettes?

http://www.dmc-kursus.dk/index.php?ContentFile=content/content_2_3.php&HeaderText=Kurser&SubMenu=menu/submenu2.php