p2-force-login.php

<?php
/* Plugin Name: P2 Force Login
 * Description: Force logged-out users to log-in in order to view the P2
 * Author: Maor Chasen
 * Author URI: http://maorchasen.com/
 * Version: 1.0
 */
 
 function p2fl_force_login() {
	is_user_logged_in() || auth_redirect();
 }
 add_action( 'parse_request', 'p2fl_force_login', 1 );