public static function generateExtAttr($owner = 07, $group = 05, $other = 05, $isFile = true) {
        $fp = $isFile ? self::S_IFREG : self::S_IFDIR;
        $fp |= (($owner & 07) << 6) | (($group & 07) << 3) | ($other & 07);

        return ($fp << 16) | ($isFile ? self::S_DOS_A : self::S_DOS_D);
    }