CakePHP路由中的字符串替换

In my application, I have a number of controllers with the same prefix. For the sake of example, let's say they are:

my_posts
my_users
my_letters

The URLs generated for these are obviously:

/my_posts/view/1
/my_users/add
/my_letters/whatever

I'd like to set up some custom routing so that I can use the URLs like this:

/my/posts/view/1
/my/users/add
/my/letters/whatever

So basically, if the URL starts with /my/ then the controller to pass to should be my_{whatever_comes_next}.

I've been looking at the documentation, but still can't figure it out.

Router::connect(
    '/my/posts/:action/*',
    array(
        'controller'=>'my_posts',
        'action'=>'index'
    )
);
Router::connect(
    '/my/users/:action/*',
    array(
        'controller'=>'my_users',
        'action'=>'index'
    )
);
[..]

agreed, that that is not quite comfortable, but it should work..

Not sure that is possible, but why not use an intermediate router?

Router::connect (
    '/my/*', 
    array (
        'controller' => 'my_router', 
        'action' => 'route',
    )
);

class MyRouterController extends AppController {
    ... 
    function route ()
    {
        $args = func_get_args ();
        $controller = array_shift ($args);
        $this->requestAction (
            'my_'.$controller.'/'.implode('/', $args), 
            array ('return' => true)
        );
    }
}