Quick and dirty WordPress router

router.php

<?php
// php -S localhost:9393 router.php
$root = $_SERVER[ 'DOCUMENT_ROOT' ];
chdir( $root );

$path = '/' . ltrim( parse_url( $_SERVER['REQUEST_URI'] )['path'], '/' );
set_include_path( get_include_path() . ':' . __DIR__ );

if ( file_exists( $root . $path ) ) {
	if ( is_dir( $root . $path ) && substr( $path, strlen( $path ) - 1, 1) !== '/' ) {
		$path = rtrim( $path, '/' ) . '/index.php';
	}
	if ( strpos( $path, '.php' ) === false) {
		return false;
	} else {
		chdir( dirname( $root.$path ) );
		require_once $root . $path;
	}
} else {
	include_once 'index.php';
}