How to require PHP files relatively (at different directory levels)?

Question

I have the following file structure:

 rootDIR     dir1         subdir1            file0.php            file1.php     dir2        file2.php        file3.php        file4.php    

file1.php requires file3.php and file4.php from dir2 like this :

require('../../dir2/file3.php') 

file2.php requires file1.php like this:

require('../dir1/subdir1/file1.php') 

But then require in file1.php fails to open file3.php and file4.php ( maybe due to the path relativeness)

However, what is the reason and what can I do for file2.php so file1.php properly require file3.php and file4.php?

Answer 1

For relative paths you can use __DIR__ directly rather than dirname(__FILE__) (as long as you are using PHP 5.3.0 and above):

require(__DIR__.'/../../dir2/file3.php'); 

Remember to add the additional forward slash at the beginning of the path within quotes.

See:

• PHP - with require_once/include/require, the path is relative to what?
• PHP - Relative paths "require"

Answer 2

Try adding dirname(__FILE__) before the path, like:

require(dirname(__FILE__).'/../../dir2/file3.php'); 

It should include the file starting from the root directory