X-Recipient: archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status: No, hits=-1.7 required=5.0	tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,T_TO_NO_BRKTS_FREEMAIL
X-Spam-Check-By: sourceware.org
MIME-Version: 1.0
In-Reply-To: <20101001015713.M64956@ds.net>
References: <1842787202 DOT 20100930054004 AT mtu-net DOT ru>	<20100930151033 DOT M76347 AT ds DOT net>	<191883817 DOT 20101001042301 AT mtu-net DOT ru>	<20101001015713 DOT M64956 AT ds DOT net>
Date: Fri, 1 Oct 2010 10:12:39 +0200
Message-ID: <AANLkTikfp18iz5dmcXtE_LskjEqepXiUEMigq3TcT0bh@mail.gmail.com>
Subject: Re: diff issue
From: Csaba Raduly <rcsaba AT gmail DOT com>
To: cygwin AT cygwin DOT com
Content-Type: text/plain; charset=ISO-8859-1
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
Precedence: bulk
List-Id: <cygwin.cygwin.com>
List-Unsubscribe: <mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT 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

Andrey Repin wrote:
>>>> When I'm comparing them with my usual macro
>>>> diff -bdu -x "CVS" -x ".svn" -I "\$Id.*\$" -I "\$Revision.*\$" -I
>>>> "\$Date.*\$" -I "\$Author.*\$" --strip-trailing-cr -- '1/backup.bat'
>>>> 'backup.bat'
>>>> It telling me that $Id$ lines are differ.
>>>> But when I remove the "@echo off" from second file, it telling me
>>>> that files are "identical" (the expected result).

Did you get something similar to the following ?

--- 1/backup.bat     2010-10-01 09:55:59.070190500 +0200
+++ backup.bat     2010-10-01 09:56:19.112194500 +0200
@@ -1,2 +1,3 @@
-rem $Id: backup.bat,v 1.1 2007/07/17 01:53:30 Daemon Exp $
+@echo off
+rem $Id: backup.bat 10 2010-09-30 01:22:14Z anrdaemon $
 rar a -ag-YYYY-MM-DD_HH-MM -- MinerTimer @MinerTimer.list

I suspect that the -I switch told diff "do not start a difference if
the line matches" rather than "consider this line to always match".

So diff found the differing "@echo" line, and went into "it's a diff"
mode until the identical "rar" line was found. So the "$Id" line is
included in the diff even though it matches the -I switch.

This behavio(u)r is counter-intuitive, but is probably required;
otherwise the generated diff would be unusable for patch(1).

On Fri, Oct 1, 2010 at 4:20 AM, Brian Wilson  wrote:
>
> I'm not sure what the "--" argument is used for (before the file names) though.

It's a convenient way to ensure that the command works with filenames
beginning with a dash.

-- 
GCS a+ e++ d- C++ ULS$ L+$ !E- W++ P+++$ L w++$ tv+ b++ DI D++ 5++
Life is complex, with real and imaginary parts.
"Ok, it boots. Which means it must be bug-free and perfect. " -- Linus Torvalds
"People disagree with me. I just ignore them." -- Linus Torvalds

--
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