包含根目录文件

这是我的应用程序的结构：

core
    application
        controller_base.class.php
        registry.class.php
        router.class.php
        template.class.php
    controller
    include
        config.php
    model
    views
index.php

文件config.php包含在index.php文件中（这没有问题），以下是它包含的内容：

<?php
/*** include the controller class ***/
include(ROOT . '/core/application/controller_base.class.php');
/*** include the registry class ***/
include(ROOT . '/core/application/registry.class.php');
/*** include the router class ***/
include(ROOT . '/core/application/router.class.php');
/*** include the template class ***/
include(ROOT . '/core/application/template.class.php');

/*** autoload model classes ***/
function __autoload($class_name) {
    $filename = strtolower($class_name) . '.class.php';
    $file = ROOT . '/core/model/' . $filename;
    if (!file_exists($file)) {
        return false;
    }
    // include the $class_name class
    include($file);
}
$registry = new registry;

你必须知道常量 ROOT 是这样定义的：

define('ROOT', str_replace('/index.php', '', $_SERVER['SCRIPT_NAME']));

此常量包含值/Lab/Livre/POO/TP1，这当然是应用程序的根。

但是我在config.php中包含的所有文件都存在问题。PHP 给我抛出一个错误，说在/Users/tom/www/Lab/Livre/POO/TP1/core/include/config.php中找不到文件。

所以问题很明显。我希望 PHP 从应用程序的根目录（索引.php所在的位置）查找文件，但它从 config.php 所在的文件夹中查找文件。

我这个问题已经有很长时间了，但我想一劳永逸地找到解决方案。

我不能让它做我想要的！我希望有人能帮助我。
谢谢。

PS：换句话说，我想使用绝对路径包含文件。

PS：这是完整的错误文本：

Warning: include(/Lab/Livre/POO/TP1/core/application/controller_base.class.php): failed to open stream: No such file or directory in /Users/tom/www/Lab/Livre/POO/TP1/core/include/config.php on line 4
Warning: include(): Failed opening '/Lab/Livre/POO/TP1/core/application/controller_base.class.php' for inclusion (include_path='.:/usr/local/php5/lib/php') in /Users/tom/www/Lab/Livre/POO/TP1/core/include/config.php on line 4
Warning: include(/Lab/Livre/POO/TP1/core/application/registry.class.php): failed to open stream: No such file or directory in /Users/tom/www/Lab/Livre/POO/TP1/core/include/config.php on line 7
Warning: include(): Failed opening '/Lab/Livre/POO/TP1/core/application/registry.class.php' for inclusion (include_path='.:/usr/local/php5/lib/php') in /Users/tom/www/Lab/Livre/POO/TP1/core/include/config.php on line 7
Warning: include(/Lab/Livre/POO/TP1/core/application/router.class.php): failed to open stream: No such file or directory in /Users/tom/www/Lab/Livre/POO/TP1/core/include/config.php on line 10
Warning: include(): Failed opening '/Lab/Livre/POO/TP1/core/application/router.class.php' for inclusion (include_path='.:/usr/local/php5/lib/php') in /Users/tom/www/Lab/Livre/POO/TP1/core/include/config.php on line 10
Warning: include(/Lab/Livre/POO/TP1/core/application/template.class.php): failed to open stream: No such file or directory in /Users/tom/www/Lab/Livre/POO/TP1/core/include/config.php on line 13
Warning: include(): Failed opening '/Lab/Livre/POO/TP1/core/application/template.class.php' for inclusion (include_path='.:/usr/local/php5/lib/php') in /Users/tom/www/Lab/Livre/POO/TP1/core/include/config.php on line 13