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 include this code at the top of every page:

//get basic page variables
$self=$_SERVER['PHP_SELF']; 
$thispath=dirname($_SERVER['PHP_SELF']);
$sitebasepath=$_SERVER['DOCUMENT_ROOT'];

//include the global settings, variables and includes

include_once("$sitebasepath/globals/global.include.php");

Include and require both take either a relative path or the full rooted path. I prefer working with the full path and make all my references like the inlcude statement above. This allows me to enter a general variable $sitebasepath that handles account specific information that may change from machine to machine and then simply type the path from the webroot, ie. /globals/whatever_file.php

I also use the $self variable in forms that may call themselves to handle data input.

Hope that helps.