Re: Login Shell/Profile: Stop the Madness

["Daniel B." <REMOVEdanielTHIS@fgm.com>]

Matthias Czapla wrote:

> On Sat, Jul 17, 2004 at 01:20:13PM -0400, Daniel B. wrote:
>
> > It would be sensible if logging in via a display manager included
> > the same shell login initialization that logging in on a virtual
> > console performed.  (Or via telnet, rlogin, ssh, etc.)
>
>
> I agree, that would be most sensible.
>
>
> > > Now do you have the display manager source every possible file that
> > > should be sourced for each possible shell? 
> >
> > No. 
> >
> > But what the display manager should do at some point is start a 
> > login shell (that is, start the user's selected shell, with the 
> > standard login flag for shell programs so that shell reads the
> > user's login-time files).
> >
> > That's what logging in to a virtual console does.
>
>
> Yes, and then this login shell keeps running and is the parent of
> any subsequently started processes. If the display manager just
> starts a login shell then this shell is unable to change the
> environment of it's parent (the dm) 

Why would it need to?   (Also, see below about running part of the
DM under a shell process.)

> and if this shell exits
> everything will be exactly as it was before it has been run.

Right, but it wouldn't be used in a way that it exits.

> So we would need to start a login shell that will become the parent
> process of everything else that you would like to have an
> initialized environment.

Exactly, except that the login shell doesn't have to the direct
parent of every other process; it just has to be an ancestor.

>  I don't know how a dm works internally to
> say if this is possible though :|

Part of the display manager (or window manager or whichever part
exactly) should invoke the user's chosen shell as a login shell
with a command telling it to run a command that invokes the rest
of the display manager (or ...).

The results are that:
- a login instance of the user's chosen interactive shell gets a
  chance to run and do its login-time initialization, the user's
  usual shell environment settings are used
- the display manager (or ...) gets control back to do everything it
  needs to do
- the environment of the second display manager process reflects
  the user's login shell environment settings
- processes spawned by that window manager process also relect the
  user's login shell environment settings


Daniel