X-Recipient:	archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status:	No, hits=-10.2 required=5.0 tests=AWL,BAYES_00,KHOP_PGP_SIGNED,KHOP_RCVD_UNTRUST,KHOP_THREADED,RCVD_IN_DNSWL_HI,SPF_HELO_PASS,T_RP_MATCHES_RCVD
X-Spam-Check-By:	sourceware.org
Message-ID:	<4FE1D93E.5060108@redhat.com>
Date:	Wed, 20 Jun 2012 08:07:58 -0600
From:	Eric Blake <eblake AT redhat DOT com>
User-Agent:	Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120605 Thunderbird/13.0
MIME-Version:	1.0
To:	cygwin AT cygwin DOT com
Subject:	Re: GNU screen not seeing $SHELL env var?
References:	<201206201320 DOT q5KDKWp4005645 AT localhost DOT localdomain>
In-Reply-To:	<201206201320.q5KDKWp4005645@localhost.localdomain>
OpenPGP:	url=http://people.redhat.com/eblake/eblake.gpg
X-IsSubscribed:	yes
Mailing-List:	contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id:	<cygwin.cygwin.com>
List-Subscribe:	<mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive:	<http://sourceware.org/ml/cygwin/>
List-Post:	<mailto:cygwin AT cygwin DOT com>
List-Help:	<mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender:	cygwin-owner AT cygwin DOT com
Mail-Followup-To:	cygwin AT cygwin DOT com
Delivered-To:	mailing list cygwin AT cygwin DOT com

--------------enigD7C2D8942B7210F6B83D157F
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

On 06/20/2012 07:20 AM, Tom Rodman wrote:

>   $ echo $SHELL
>   /bin/bash
>   $ bash -c 'echo SHELL: $SHELL'  # does this prove SHELL is exported?
>   SHELL: /bin/bash

No.  And in fact, bash does not export SHELL by default, but defaults to
defining SHELL as a shell-local variable.  You have to explicitly export
it yourself if you want child processes to see it.

$ env -u SHELL bash -c 'echo $SHELL'
/bin/bash
$ env -u SHELL bash -c 'env | grep SHELL'
$ env -u SHELL bash -c 'export SHELL; env | grep SHELL'
SHELL=3D/bin/bash
$

--=20
Eric Blake   eblake AT redhat DOT com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org




--------------enigD7C2D8942B7210F6B83D157F
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature
Content-Disposition: attachment; filename="signature.asc"

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)
Comment: Public key at http://people.redhat.com/eblake/eblake.gpg
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/

iQEcBAEBCAAGBQJP4dk+AAoJEKeha0olJ0NqKqUH/2R1r6/H3XDV+/ddmBnFny1x
ruCAZc9jjsFaLjI1vqVB5EHOFwoXE0TNa/XgXymxL7NbRyMeWSEJHL2s30CiQT2g
lBEjpPzUZcMgwsFWffYma771Ws4cqLKF8zDcwk6HJnxR63kjGQgY/YMhWt9/4iN7
LEmwHYfSCmgVdYLZ7+nEugzT6r/PU1HjeEj4965v3yWdxShQsvzfs3vvKiAwQzo9
Z5aAu2/jSclF5m4M2u9LSB0UygzV+miWWwrRq/+LL/fzQpbHgCPnh0Y7F/N9kEnw
sapXYmAUfr3Ahjm+FgHq8XOuBZeJgw60HffxpD6yJgaxGdcbPjdASXpDQl7UpLg=
=Vu62
-----END PGP SIGNATURE-----

--------------enigD7C2D8942B7210F6B83D157F--

- Raw text -