note 107614 added to language.constants.predefined

You cannot check if a magic constant is defined. This means there is no point in checking if __DIR__ is defined then defining it. defined('__DIR__') always returns false. Defining __DIR__ will silently fail in PHP 5.3+. This could cause compatibility issues if your script includes other scripts. Here is proof: <pre><?php echo (defined('__DIR__') ? '__DIR__ is defined' : '__DIR__ is NOT defined' . PHP_EOL); echo (defined('__FILE__') ? '__FILE__ is defined' : '__FILE__ is NOT defined' . PHP_EOL); echo (defined('PHP_VERSION') ? 'PHP_VERSION is defined' : 'PHP_VERSION is NOT defined') . PHP_EOL; echo 'PHP Version: ' . PHP_VERSION . PHP_EOL; ?></pre> Output: __DIR__ is NOT defined __FILE__ is NOT defined PHP_VERSION is defined PHP Version: 5.3.6 ---- Server IP: 69.147.83.197 Probable Submitter: 58.161.120.188 ---- Manual Page -- http://www.php.net/manual/en/language.constants.predefined.php Edit -- https://master.php.net/note/edit/107614 Del: integrated -- https://master.php.net/note/delete/107614/integrated Del: useless -- https://master.php.net/note/delete/107614/useless Del: bad code -- https://master.php.net/note/delete/107614/bad+code Del: spam -- https://master.php.net/note/delete/107614/spam Del: non-english -- https://master.php.net/note/delete/107614/non-english Del: in docs -- https://master.php.net/note/delete/107614/in+docs Del: other reasons-- https://master.php.net/note/delete/107614 Reject -- https://master.php.net/note/reject/107614 Search -- https://master.php.net/manage/user-notes.php