<?php

function parse($url) {
	$url = trim($url, '/');
	$params = explode('/', $url);
	
	var_dump($params);
}

parse('/site/blog/app/');

array(3) {
  [0]=>
  string(4) "site"
  [1]=>
  string(4) "blog"
  [2]=>
  string(3) "app"
}