I'm working on an app (WIODE of course...) and trying to build a method for linking back to the config file. Problem is that it's not a definite. Plus, now I'm trying to set it when symlink'ing to the system folder. Here's a little function to handle this...

Instead of:

require_once('../../../config.php');

...which works well UNLESS I'm using symlinked assets, I use:

function changeDir($up_n){
  $split = explode("/",$_SERVER['SCRIPT_FILENAME']);
  array_pop($split); // Remove current file name
  for ($i=1; $i<=$up_n; $i++){ array_pop($split); }
  return implode("/",$split);
}

require_once(changeDir(3)."/config.php");

Pretty simple, works no matter where the DOCUMENT_ROOT is or if I'm using a symlink.

Nothing fancy, but it works well. No matter where I install the application or how I'm linking to the system files it works (dig into the WIODE code if you want an example).