Difference Between getcwd() and dirname(__FILE__) ? Which should I use?

Question

In PHP what is the difference between

getcwd()
dirname(__FILE__)

They both return the same result when I echo from CLI

echo getcwd()."\n";
echo dirname(__FILE__)."\n";

Returns:

/home/user/Desktop/testing/
/home/user/Desktop/testing/

Which is the best one to use? Does it matter? What to the more advanced PHP developers prefer?

Answer 1

__FILE__ is a magic constant containing the full path to the file you are executing. If you are inside an include, its path will be the contents of __FILE__.

So with this setup:

./foo.php

<?php
echo getcwd() ,"\n";
echo dirname(__FILE__),"\n" ;
echo '-------',"\n";
include 'bar/bar.php';

./bar/bar.php

<?php
echo getcwd(),"\n";
echo dirname(__FILE__),"\n";

You get this output (Windows / Zend Studio Debugger):

C:\Users\me\Zend\workspaces\DefaultWorkspace7\random
C:\Users\me\Zend\workspaces\DefaultWorkspace7\random
-------
C:\Users\me\Zend\workspaces\DefaultWorkspace7\random
C:\Users\me\Zend\workspaces\DefaultWorkspace7\random\bar

Appearantly, getcwd returns the directory where the file you started executing resided, while dirname(__FILE__) is file-dependant.