Re: user flags in public temp space (was Re: chflags() [heads up])

[tim () NIGHT-SHADE DEMON CO UK (Tim Fletcher)]

> I think I defeated myself in trying to explain the implementation I was
> trying to describe.  For each user, when they login, a virtual /tmp is
> created and that is shared between all sessions that user has.  This is
> setup at login time and is carried forth to all children, root or not,
> and cannot be reset (somewhat akin to chroot) unless devious methods are
> employed (i.e. write to /dev/mem).
>
> So if I have 10 logins to host foo, each login sees the same /tmp, even
> the root shells I generate via su/sudo in half.  If I login as root, I
> don't have the same /tmp (I get a different one).  cron/at jobs would
> be no different.  So the `real' /tmp could even be 755 root.wheel.

I see what you are getting at basically /tmp becomes an extention to the
per user memory space. (bad analogy on my part but I can't think of a
better one :)

Although it does rather cripple /tmp in another way: That of sharing
information between users. If I tell another user that the file s/he wants
is in /tmp (as my /home/tim dir is 711 with most files 600) I don't have
to mess with file perms and s/he doesn't have to get the exact right name
to read the file.

You also may have problems as the /tmp space you suggest (~/tmp mapped to
/tmp) is then inside a users quota'ed directory which is often a bad idea,
this blocks logins as no tmp space is avalible hence login fails, so you
can clear out your ~/tmp space, a chicken / egg problem :). You are all
well and good quotaing or mounting /tmp to stop / filling up but the point
is the the /home and /tmp quotas should be different.

--

      Tim Fletcher                  .~.
                                    /V\       L   I   N   U   X
   tjdf () st-andrews ac uk           // \  >Don't fear the penguin<
tim () night-shade demon co uk       /(   )\
                                   ^^-^^

"First they ignore you. Then they laugh at you.
   Then they fight you. Then you win." - Gandhi