Convert relative path to absolute path

rel2abs.php

<?php
	function absolute($base, $relative) {
		$stack = explode('/', $base);
		array_pop($stack);

		foreach (explode('/', $relative) as $part) {
			if ($part === '.') {
				continue;
			}

			if ($part === '..') {
				array_pop($stack);

				continue;
			}

			array_push($stack, $part);
		}

		return implode('/', $stack);
	}