How to check whether or not a logged-in user has access to the php script that is currently being called

I've read quite a few posts that are very similar to the question I'm about to ask, but I just wanted to be sure that there wasn't a more sophisticated way to do this. Any feedback is greatly appreciated.

I want to create a mechanism to check whether or not a logged-in user has access to the php script that is currently being called. If so, the script will continue on; if not, the script just fails out using something like die('you have no access').

I came up with two ways of accomplishing this:

(please assume my session stuff is coded/working fine - i.e. I call session_start(), set up the session vars properly and etc)

1. Define a global variable first, then check the global variable in a required header file. For example:

   Content of current_executing_script.php:

   // the role the logged in user must have to continue on   
   $roleNeedToAccessThisFile = 'r';
   require 'checkRole.php''
   

   Content of checkRole.php:

   if ($_SESSION['user_role'] != $roleNeedToAccessThisFile) die('no access for you');
   

2. Define a function within the header file and call the function immediately after including/requiring it:

   Content of checkRole.php:

   function checkRole($roleTheUserNeedsToAccessTheFile) {
       return ($_SESSION['user_role'] == $roleTheUserNeedsToAccessTheFile);
   }

   Content of current_executing_script.php:

   require 'checkRole.php';
   checkRole('r') or die('no access for you');

I'm wondering if there is a way to basically just pass a parameter to checkRole.php as part of the include or require construct?

Thanks in advance.