class tracker
{
    static $files = array (
            'included' => array (),
            'required' => array (),
            'required_once' => array ()
            );

    static function check ($file)
    {
        $cFile = str_replace($_SERVER['SCRIPT_NAME'], "", $_SERVER['SCRIPT_FILENAME']);
        if (!file_exists($cFile))
            print "Error: file doesn't exists";
    
    }

    static function include ($file)
    {
        if (in_array($file, self::$files['included']))
            return include($file);
        else
        {
            array_push(self::$files['included'], $file);
            return include($file);
        }
    
    }

    static function show ()
    {
        for ($i = 0; $i < sizeof(self::$files['included']); $i++)
        {
            print self::$files['included'][$i]."<br />";
        }
        for ($i = 0; $i < sizeof(self::$files['required']); $i++)
        {
            print self::$files['required'][$i]."<br />";
        }
        for ($i = 0; $i < sizeof(self::$files['required_once']); $i++)
        {
            print self::$files['required_once'][$i]."<br />";
        }
    }

}