Re: What's in a group?

[Marcus Brinkmann]

At Sun, 19 Mar 2006 17:58:16 -0500,
Thomas Schwinge <address@hidden> wrote:
> 
> On Sun, Mar 19, 2006 at 11:17:48PM +0100, Marcus Brinkmann wrote:
> > But what corresponds to the Unix group concept?  I have identified two
> > semantic uses for a "group":
> > 
> > 1) Sharing information and authorization.  Ie, allow communication
> >    among users of the same group.
> > 
> > 2) Provide durable storage that is not associated with any particular
> >    member of the group.
> 
> 3) Hindrance of the above.
> 
> #v+
> $ groups
> users foo
> $ ls -l /tmp/not-for-fooers
> -rw----rw- 1 thomas foo 0 Mar 19 23:45 /tmp/not-for-fooers
> $ cat /tmp/not-for-fooers
> cat: /tmp/not-for-fooers: Permission denied
> #v-

I'm disgusted!

> I don't know if there's a real-world example of this facility being used,
> though.

I sincerely hope there isn't.  Otherwise it would rank very high in my
list of horrible Unix idiosyncrasies.

In a capability system, the right way not to share something is, uhm,
not to share it, of course.

Thanks,
Marcus