public function mkDir($name, $recursive = null, $chmod = null)
    {
        // test the recursive mode with default value
        $recursive = ($recursive === null) ? $this->recursiveDirectories : $recursive;
        // test the chmod with default value
        $chmod = ($chmod === null) ? $this->defCHMOD : $chmod;
        if (!is_dir($name)) {
            return (mkdir($name)) ? true : false;
        }

        return false;
    }