PHP: global vars for normalizing the ROOT and HTTP paths of the app.

PHP-normalize_global_path

<?php
// a.php: assuming this included everywhere at very first line 
// and located in root directory
// preferable, define a constant instead of variable, cos it 
// may used in functions directly without "global $ROOT";

// to use for "include"
define('ROOT', __DIR__); // for PHP >= 5.3
define('ROOT', realpath(dirname(__FILE__)));  // for PHP < 5.3
// to use for "src,href"
define('HTTP', 'http://www.mydomain.com/');

// includes
include ROOT .'/layout_header.php';
include ROOT .'/classes/mailer.php';
include ROOT .'/foo/bar/baz.php';
...

// src,href
printf('<img src="%s/img/lollipop.png" />', HTTP);
printf('<script src="%s/js/move.js" />', HTTP);
print '<a href="'. HTTP .'/aFolder/movement.php">Click here!</a>';
...

// inline without global vars includes
define('ROOT', realpath(__DIR__ . '/../')); 

?>