disabling interactive shell in ssh session

[Lubos Vrbka <lubos.vrbka@gmail.com>]

hi guys,

some time ago i asked how is it possible to allow only rsync (and 
similar) services in ssh connections. the ultimate answer was rssh.

now a related problem... if i want to have ssh login allowed, however 
user wouldn't get shell prompt, how shall i do it?

i.e.
ssh machine
results in logout, maybe with some error message
ssh machine "ls -la"
prints out the contents of the home directory on that machine

thanks for any hints / pointers to the relevant docs...

regards.

--
Lubos
_@_"