如何使用PHP从Web根目录外部提供文档？

我认为这样会起作用：

<?php$path = realpath(dirname(__FILE__) . '/../my_files/' . $_GET['file']);$parts = explode('/', pathinfo($path, PATHINFO_DIRNAME));if (end($parts) !== 'my_files') {    // LFI attempt    exit();}if (!is_file($path)) {    // file does not exist    exit();}header('Content-Type: ' . mime_content_type($path));header('Content-Length: ' . filesize($path));readfile($path);