public function absolutize()
    {
        $new = [];
        $path = $this->path;
        if ($path[0] !== '/') $path = $this->cwd . DS . $this->path;
        $paths = explode(DS, $path);
        foreach ($paths as $p) {
            switch ($p) {
                case '.':
                    break;
                case '..':
                    array_pop($new);
                    if (!$new) $new[] = '';
                    break;
                default:
                    $new[] = $p;
                    break;
            }
        }
        $this->path = join(DS, $new);
    }