//自动登录
function auto_login() {
    if (!is_user_logged_in()) {
        //determine WordPress user account to impersonate
        $user_login = 'guest';

       //get user's ID
        $user = get_userdatabylogin($user_login);
        $user_id = $user->ID;

        //login
        wp_set_current_user($user_id, $user_login);
        wp_set_auth_cookie($user_id);
        do_action('wp_login', $user_login);
    }
}
//退出登录
add_action( 'wp_logout', 'my_logout_action' );
function my_logout_action( $user_id ){
    @wp_logout();
}