Mine

class tracker{    static $files = array (            'included' => array (),            'required' => array (),            'required_once' => array ()            );    static function check ($file)    {        $cFile = str_replace($_SERVER['SCRIPT_NAME'], "", $_SERVER['SCRIPT_FILENAME']);        if (!file_exists($cFile))            print "Error: file doesn't exists";        }    static function include ($file)    {        if (in_array($file, self::$files['included']))            return include($file);        else        {            array_push(self::$files['included'], $file);            return include($file);        }        }    static function show ()    {        for ($i = 0; $i < sizeof(self::$files['included']); $i++)        {            print self::$files['included'][$i]."<br />";        }        for ($i = 0; $i < sizeof(self::$files['required']); $i++)        {            print self::$files['required'][$i]."<br />";        }        for ($i = 0; $i < sizeof(self::$files['required_once']); $i++)        {            print self::$files['required_once'][$i]."<br />";        }    }}