WordPress 301跳转旧链接方法

add_action('template_redirect', function () {
    if (is_singular('product')) {
        $old_url = home_url('/product/' . get_query_var('name'));
        $new_url = home_url('/' . get_query_var('name'));
        if (untrailingslashit($old_url) !== untrailingslashit($new_url)) {
            wp_redirect($new_url, 301);
            exit;
        }
    }
});