X-Recipient: archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status: No, hits=-2.5 required=5.0 	tests=AWL,BAYES_00,SPF_PASS
X-Spam-Check-By: sourceware.org
Message-ID: <4AFE1399.9040500@gmail.com>
Date: Sat, 14 Nov 2009 02:19:05 +0000
From: Dave Korn <dave DOT korn DOT cygwin AT googlemail DOT com>
User-Agent: Thunderbird 2.0.0.17 (Windows/20080914)
MIME-Version: 1.0
To: cygwin AT cygwin DOT com
Subject: Re: [BUG] fopen(..., "a") does not seek to end of file until some   write operation
References: <592384 DOT 26227 DOT qm AT web52612 DOT mail DOT re2 DOT yahoo DOT com> <4AFDC46A DOT 3070503 AT byu DOT net>
In-Reply-To: <4AFDC46A.3070503@byu.net>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.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

Eric Blake wrote:

> According to Salvador Fandino on 11/13/2009 1:36 PM:

>> Using ftell() after fopen(..., "a") returns 0 even when the file open for appending is not empty. AFAIK, it should return the size of the file.
> 
> Not a bug.  POSIX allows this behavior, and Linux does it as well.  POSIX
> also allows BSD behavior of seeking to the end, although this is less
> friendly to reading back a file opened with fopen(...,"a+").  So portable
> programs can't expect either situation, and you MUST use fseek when
> opening for append if you expect a particular position.

  I'm really confused; aren't you saying that there is exactly no difference
between opening for append and just opening in ordinary r/w mode?  I always
thought the positioning of the write pointer immediately after open was the
only possible difference there could be.

    cheers,
      DaveK

--
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