Simple PHP "Get Application Root" Function

siteroot.php

<?php 

function getSiteRoot() 
{
	$docRoot = str_replace("\\", "/", $_SERVER['DOCUMENT_ROOT']);
	$fileDir = str_replace("\\", "/", dirname(__FILE__));
	$cut = explode($docRoot, $fileDir);
	if (count($cut) > 1) {
		return $cut[1];
	}
	return $fileDir;
}