Normalize a path in PHP

path.php

<?php
/**
 * Normalize a path.
 *
 * Usage: path('./one/', '/two/', 'three/');
 * Result: "./one/two/three"
 * @param array $parts
 * @return string
 */
function path(...$parts) {
    $parts = array_filter($parts);
    $first = rtrim(array_shift($parts), DIRECTORY_SEPARATOR);
    $parts = array_map(function ($value) {
        return trim($value, DIRECTORY_SEPARATOR);
    }, $parts);
    array_unshift($parts, $first);
    return join(DIRECTORY_SEPARATOR, $parts);
}