Debian bug report logs - #617, boring messages

Message sent to debian-devel@pixar.com:

Subject: Bug#617: prerm script doesn't have default response to prompt
Reply-To: iwj10@cus.cam.ac.uk (Ian Jackson), debian-bugs@pixar.com
Resent-To: debian-devel@pixar.com
Resent-From: iwj10@cus.cam.ac.uk (Ian Jackson)
Resent-Sender: iwj10@cus.cam.ac.uk
Resent-Date: Thu, 23 Mar 1995 14:18:07 GMT
Resent-Message-ID: <debian-bugs-handler.617.032314075615157@pixar.com>
X-Debian-PR-Package: xbaseR6
X-Debian-PR-Keywords: 
Received: via spool for debian-bugs; Thu, 23 Mar 1995 14:18:07 GMT
Received: with rfc822 via encapsulated-mail id 032314075615157;
          Thu, 23 Mar 1995 14:07:56 GMT
Received: from pixar.com by mongo.pixar.com with smtp
	(Smail3.1.28.1 #15) id m0rrnWt-00062HC; Thu, 23 Mar 95 06:06 PST
Received: from bootes.cus.cam.ac.uk by pixar.com with SMTP id AA23088
  (5.65c/IDA-1.4.4 for <debian-bugs@pixar.com>); Thu, 23 Mar 1995 06:06:17 -0800
Received: by bootes.cus.cam.ac.uk
	(Smail-3.1.29.0 #30) id m0rrnL9-000BzrC; Thu, 23 Mar 95 13:54 GMT
Received: by chiark (Smail3.1.28.1 #3)
	id m0rrljE-0002gOZ; Thu, 23 Mar 95 12:11 GMT
Message-Id: <m0rrljE-0002gOZ.ijackson@nyx.cs.du.edu>
Date: Thu, 23 Mar 95 12:11 GMT
From: iwj10@cus.cam.ac.uk (Ian Jackson)
To: debian-bugs@pixar.com
In-Reply-To: <9503221432.AA23154@bb29c.mdd.comm.mot.com>
References: <9503221432.AA23154@bb29c.mdd.comm.mot.com>

Bill Mitchell writes:
> I'm inclined to agree with Ian here that the script shouldn't loop
> (and some of my postinst scripts may loop in this situation -- I'd need
> to check them to be sure).
>
> However, saying "this is a bug" at this point may be a bit strong. Do
> the packaging guidelines which maintainers have used to write these scripts
> require scripts to exit with non-zero return values if presented with EOF
> in response to a prompt?

The packaging guidelines require a script to give a non-zero exit
status if *ANY* error occurs which means that the processing should
not continue.

EOF on stdin is merely a special case of this (unless the script can
do without the response, I suppose).

In fact, postinst scripts are simply a more general case of programs -
all of which should reflect errors in their exit status.  This is
vitally important, despite the fact that many of the original Unix
programs are braindead in this respect.  If programs don't give
correct error indications it is impossible to build a reliable system.

Furthermore, a program which goes into a tight loop when its stdin
goes away is clearly broken.  The HP system at the Engineering
Department here is full of such programs - I suspect a bug in the libc
- and they eat up huge amounts of CPU time to no good effect.

> Once the dust from the release settles, we probably need a second pass
> at the Guidelines, followed by review of the packages for Guidelines
> compliance.

This is not a Guidelines issue.  This is a programming quality issue.
NB, I'm tarring myself with the same brush here - many of my scripts
don't check for errors and will loop indefinitely.  I'll issue new
versions of the affected packages.

Ian.

Message sent:

From: iwj10@thor.cam.ac.uk (Ian Jackson)
To: iwj10@cus.cam.ac.uk (Ian Jackson)
Subject: Bug#617: Info received (was Bug#617: prerm script doesn't have default response to prompt)
In-Reply-To: <m0rrljE-0002gOZ.ijackson@nyx.cs.du.edu>
References: <m0rrljE-0002gOZ.ijackson@nyx.cs.du.edu>

Thank you for the additional information you have supplied regarding
this problem report.  It has been forwarded to the developers to
accompany the original report.

If you wish to continue to submit further information on your problem,
please do the same thing again: send it to debian-bugs@pixar.com, ensuring
that the Subject line starts with "Bug#617" or "Re: Bug#617" so that
we can identify it as relating to the same problem.

Please do not reply to the address at the top of this message,
unless you wish to report a problem with the bug-tracking system.

Ian Jackson
(maintainer, debian-bugs)