function urlDondur($metin)
{
    $url = '/(https?:\/\/|www\.)?(\S+)/i';
    return preg_replace_callback($url, function($matches) {
        $protocol = $matches[1] ? $matches[1] : '';
        $url = $protocol . $matches[2];
        return '<a href="' . $url . '" target="_blank" title="' . $url . '">' . $url . '</a>';
    }, $metin);
}