// checks if a user is logged in, if not redirect them to the login page
function auth_redirect_login() {
$user = wp_get_current_user();
if ( $user->id == 0 ) {
nocache_headers();
wp_redirect(get_option('siteurl') . '/wp-login.php?redirect_to=' . urlencode($_SERVER['REQUEST_URI']));
exit();
}
}