Including relative files with PHP

Consider the following 3 php files in this directory structure:

   ./c.php
   ./1/b.php
   ./1/2/a.php

Consider you want to access c.php via the browser, which depends on b.php, which in turn depends on a.php.

Files and their contents are listed below

• 1/2/a.php

This is a.php
<?
  include('../b.php');
?>

• 1/b.php

This is b.php
<?
  include('../c.php');
?>

• c.php

This is c.php

Now when you access the url 1/2/a.php, the script successfully includes b.php, but not c.php. We received the following warnings

This is a.php This is b.php
Warning: main(../c.php): failed to open stream: No such file or directory in /home/www/test/1/b.php on line 3

Warning: main(../c.php): failed to open stream: No such file or directory in /home/www/test/1/b.php on line 3

Warning: main(): Failed opening '../c.php' for inclusion (include_path='./:/usr/local/lib/php') in /home/www/test/1/b.php on line 3

The problem is that it tries to open ../c.php relative to the first file, 1/2/a.php, even though the include was made inside b.php.

The solution is to use __FILE__, and dirname to get the directory of the current php file.

1/b.php should look like

This is b.php
<?
  include(dirname(__FILE__).'/../c.php');
?>