PHP variables and stuffs Options

[Mikeplyts]

I'm working on a little something-something and I was wondering if I could use variables or placeholders or whatever in a switch function based on the URL. Sort of like Apache.

Um, something like this:

CODE

<?php
$uri = $_SERVER['SCRIPT_NAME'];

switch($uri) {
    case '/$1/$2/$3/index.php':
        echo 'Under 3 directories.';
        break;
    case '/$1/$2/$3/$4/index.php':
        echo 'Under 4 directories.';
        break;
}
?>

Get what I mean? And yes, I've tried the above but it doesn't seem to work. Help would be appreciated.