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_LOW
X-Spam-Check-By: sourceware.org
MIME-Version: 1.0
In-Reply-To: <32903475.post@talk.nabble.com>
References: <32903475 DOT post AT talk DOT nabble DOT com>
Date: Fri, 2 Dec 2011 12:19:46 -0500
Message-ID: <CAG_2cTn_1UHZy-13ACu-EPMaUSSSOr38s1_Rc0ccmdS2JDyJSQ@mail.gmail.com>
Subject: Re: Redirecting output from running proc doesn't modify the "last modified time" field for target file
From: Jon Clugston <jon DOT clugston AT gmail DOT com>
To: cygwin AT cygwin DOT com
Content-Type: text/plain; charset=ISO-8859-1
X-IsSubscribed: yes
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
Content-Transfer-Encoding: 8bit
X-MIME-Autoconverted: from quoted-printable to 8bit by delorie.com id pB2HKB0f010030

On Fri, Dec 2, 2011 at 11:51 AM, ajshower <ajshower AT gmail DOT com> wrote:
>
> I've got a bash script running in Cygwin whose output has been redirected to
> another file.  MS-DOS exhibits this same behavior if I run the bash script
> as a batch job.
>
>    bash.exe &> log.txt
>
> Adding content to log.txt through redirection does not change log.txt's last
> modified time while bash.exe is executing.
>
> Baseline:
>    # ls -la --full-time log.txt
>    -r-xr-x---+ 1 user Domain Users 66455 2011-11-30 16:16:45.246664800
> -0500 log.txt
>
> Some time later:
>    # ls -la --full-time log.txt
>    -r-xr-x---+ 1 user Domain Users 66838 2011-11-30 16:16:45.246664800
> -0500 log.txt
>
> Note that even though log.txt has gotten larger, the last modified time has
> not changed.  The last modified time is updated only when bash.exe
> terminates.
>
> Ubuntu 11.04 handles this scenario, IMO, correctly.  Is there a way I can
> get the last modified time to be updated when the content of the file
> changes and while bash.exe is executing?
>
> Cygwin:  CYGWIN_NT-6.1
> MS-DOS:  Microsoft Windows [Version 6.1.7601]
>

I don't see how this could be a Cygwin issue.  If writing to a file
(while it is open) doesn't immediately update the last modified time
on Windows, there is no reasonable way for Cygwin to "fix" that.

IMHO, this is a very dubious "feature" to depend upon.  If you want to
know if the file has changed, why not check its length instead?

Jon

--
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