How do you know the correct path to use in a PHP require_once() statement

Question

As many do I have a config.php file in the root of a web app that I want to include in almost every other php file. So most of them have a line like:

require_on         


        

Answer 1

I use the dirname(__FILE__) thing like bobwienholt most the time, but what it could pay to do is have a base entry point that loads all your other code that defines a constant refereing to the root of the project, ie

define("ROOT",dirname(__FILE__).'/' ); 

and then later all you need to know is where the path is relative to root, ie:

require(ROOT . "/lib/tool/error.php"); 

note,

you should REALLY avoid paths with "../" at the start of them, they are not relative to the file, but relative to where you ARE and this creates broken-ass code.

 cd foo
 php bar/baz.php 
 -> some error saying it cant find the file
 cd bar 
 php baz.php 
 -> suddenly working.

Important

If you use "../" notation, it takes complete ignorance of the PHP Include Path, And ONLY considers where the person whom is running it is.