Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ames!nrl-cmf!cmcl2!brl-adm!brl-smoke!gwyn
From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.unix.wizards
Subject: Re: grep replacement
Message-ID: <8102@brl-smoke.ARPA>
Date: 16 Jun 88 09:08:43 GMT
References: <16173@brl-adm.ARPA>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 18

In article <16173@brl-adm.ARPA> rbj@ICST-CMR.ARPA (Root Boy Jim) writes:
>Distrubuting non-context diffs in a source group
>should be considered a felony. Context diffs are a feature that have
>been proven useful time and time again.

I have to disagree with the sentiment that "diff -c" is extremely
useful.  I find it only slightly useful.

You might have noticed that when I post bug fixes I never do it
via "diff -c".  I prefer to give enough information to RELIABLY
patch the code.  In any context where I would trust "patch", I
would also trust "ed" using the output of "diff -e", which is
generally much less output.  (By the way, this could also be
done with a separate filter applied to normal "diff" output.)

I recently generated a "diff -c -b" comparison between SVR2 sh
sources and the BRL version of sh.  The output was larger than
the concatenation of all the sources.  It was useful for the
intended purpose (browsing), but would be ludicrous for "patch"ing.