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Date:	Fri, 13 Nov 2009 15:50:47 -0500
From:	"Roger K. Wells" <ROGER DOT K DOT WELLS AT saic DOT com>
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To:	cygwin AT cygwin DOT com
Subject:	Re: [BUG] fopen(..., "a") does not seek to end of file until some write operation
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Eric Blake wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
>
> According to Salvador Fandino on 11/13/2009 1:36 PM:
>   
>> Hii
>>
>> 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.
>
>   
however writing will always take place at the end of the file.
"Opening a file with append mode (a as the first character in the mode 
argument) shall cause all
subsequent writes to the file to be forced to the then current 
end-of-file, regardless of intervening
calls to fseek( )."
rw
> - --
> Don't work too hard, make some time for fun as well!
>
> Eric Blake             ebb9 AT byu DOT net
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-- 
Roger Wells, P.E.
SAIC
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