Date: Mon, 13 Mar 2000 19:46:32 -0500
From: Daniel Martin <Daniel.Martin@jhu.edu>
Subject: dpkg: Set useful environment variables on subshells
To: submit@bugs.debian.org
Message-id: <E12UfTk-0005KJ-00@localhost>

Package: dpkg
Version: 1.6.11
Severity: wishlist

It would be nice, when doing a long upgrade that asks many 'this config
file changed'-type questions, to have available to the subshell that is
spawned when one chooses "Z" some environment variables which specify
the names of the old and new configuration files.  This would allow
sysadmins to write small shell scripts (or whatever) that presented the
information they need to know about the two config. files.

For example, what I envision is that when dpkg spawns a subshell it sets
the following environment variables:
DPKG_SHELL_REASON=configfile-examine
DPKG_OLDCONFIGFILE=/etc/X11/xdm/xdm.options
DPKG_NEWCONFIGFILE=/etc/X11/xdm/xdm.options.dpkg-new

I could then write a shell script that takes these environment variables
and (in my case) calls on xemacs to load both files, set the new one
read-only, and start up an ediff session.  Other people who prefer other
methods could do whatever it is they prefer; what I'm asking for is just
the environment variables.

-- System Information
Debian Release: woody
Kernel Version: Linux cush 2.2.13 #2 Sun Nov 7 23:06:28 EST 1999 i586 unknown

Versions of the packages dpkg depends on:
ii  libc6          2.1.3-7        GNU C Library: Shared libraries and Timezone
ii  libncurses5    5.0-6          Shared libraries for terminal handling
ii  libstdc++2.10  2.95.2-7       The GNU stdc++ library