Date: Fri, 19 Feb 2010 11:42:56 -0500
From: Christopher Faylor <cgf-use-the-mailinglist-please AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: ssh + patch + $TMP
Message-ID: <20100219164255.GC11137@ednor.casa.cgf.cx>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <1266525566 DOT 7752 DOT 1360709921 AT webmail DOT messagingengine DOT com>  <20100218205202 DOT GY5683 AT calimero DOT vinschen DOT de>  <20100218212503 DOT GA29260 AT ednor DOT casa DOT cgf DOT cx>  <20100219121253 DOT GA5683 AT calimero DOT vinschen DOT de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20100219121253.GA5683@calimero.vinschen.de>
User-Agent: Mutt/1.5.20 (2009-06-14)
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Precedence: bulk
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com

On Fri, Feb 19, 2010 at 01:12:53PM +0100, Corinna Vinschen wrote:
>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?

I guess so.  On further reflection, I'd actually be happy to just
provide a POSIX-only environment and nuke things like SYSTEM* and WIN*.
But that's probably excessively mean.

cgf

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple