On Thu, 17 Mar 2016 18:38:56 -0400, Rich Freeman wrote:

> > umask is just not viable either, as a) it's global and affects all
> > files a user creates and b) by definition umask is modifiable by the
> > user (it's a feature to help users out so they don't need to chmod
> > every file every time) and c) you can't stop them doing it (by
> > design).  
> 
> Actually, this is completely viable.  Just set the default umasks to
> 007, and create a new group for each user as their default group (and
> don't have all their home directories be owned by some users group).
> This is how this sort of situation was handled long before POSIX ACLs
> became common, and I know that some distros behave this way by default
> for this reason (this was the case in the distro I used right before I
> switched to Gentoo).
> 
> If users chmod a file then tell them not to.  If you must, set up some
> cron job to clean up after them.
> 
> But, you can of course do this with ACLs as well.  I haven't tried
> setting those up personally.

I've done this with ACLs in the past, which is why I suggested it, but
it's a pain to set up if you haven't used them before. Alan's suggestion
of using inotify is probably simplest. Install incrond and put something
like this in a file in /etc/incron.d

/shared/dir IN_CREATE,IN_MODIFY chmod g+w $#


-- 
Neil Bothwick

Windows Error #56: Operator fell asleep while waiting.