Re: ssh + patch + $TMP

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On Feb 18 16:25, Christopher Faylor wrote:
> On Thu, Feb 18, 2010 at 09:52:02PM +0100, Corinna Vinschen wrote:
> >In contrast to other systems, sshd for Cygwin preserves a couple of
> >environment variables from the parent sshd process running under the
> >cyg_server account.  The list of preserved variables is:
> >
> >  ALLUSERSPROFILE
> >  COMMONPROGRAMFILES
> >  COMPUTERNAME
> >  COMSPEC
> >  CYGWIN
> >  NUMBER_OF_PROCESSORS
> >  OS
> >  PATH
> >  PATHEXT
> >  PROCESSOR_ARCHITECTURE
> >  PROCESSOR_IDENTIFIER
> >  PROCESSOR_LEVEL
> >  PROCESSOR_REVISION
> >  PROGRAMFILES
> >  SYSTEMDRIVE
> >  SYSTEMROOT
> >  TMP
> >  TEMP
> >  WINDIR
> >
> >Is it time to reduce this list?  Should sshd remove TMP and TEMP?
> >Anything else?
> 
> I'd say that it should only preserve COMSPEC, CYGWIN, SYSTEMDRIVE,
> SYSTEMROOT, WINDIR, and, I guess, PATH.  The other stuff is pretty
> useless anyway.  You can't reliably depend on, e.g., PROCESSOR_REVISION
> environment variable to be accurate any more than you can rely on email
> that says "Certified spam free" to be spam free.
> 
> I hate to see the environment polluted this way but, then, linux does
> it too.

Your's and Larry's reply follow two different ideas.  I'm still not
quite sure what to drop and what to keep.

I have a hard time to believe that anybody uses the PROCESSOR_foo stuff
in any script, so they can probably go without anybody noticing(*).

The TMP and TEMP really clash due to the user switch, so they should go.

CYGWIN is a no-brainer.

PATH is definitely necessary, as is probably SYSTEMDRIVE, SYSTEMROOT,
WINDOR, COMSPEC, and CYGWIN.

PATHEXT is used by the default COMSPEC, so I assume we should better
keep it.

ALLUSERSPROFILE, COMMONPROGRAMFILES, and PROGRAMFILES could be used in
scripts, though I don't really expect it.  Maybe in batch files.  Most
of the stuff in the *PROGRAMFILES dirs are GUI applications which are
not available anyway.  Looks not exaclty important in a ssh session.

COMPUTERNAME and OS could easily be used in scripts, but they don't
keep any information which isn't available in Cygwin by other means
(hostname, uname).  However, there are batch files...

Well, here's the revised list of what I think should be kept:

  ALLUSERSPROFILE
  COMPUTERNAME
  COMSPEC
  CYGWIN
  OS
  PATH
  PATHEXT
  SYSTEMDRIVE
  SYSTEMROOT
  WINDIR

Can we agree on that?


Thanks,
Corinna

(*) Famous last words?

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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