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Date: Mon, 7 Mar 2011 16:43:30 +0100
From: Corinna Vinschen <corinna-cygwin AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Cc: tar-list <bug-tar AT gnu DOT org>
Subject: Re: tar --atime-preserve with an empty file triggers a warning
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On Mar  7 08:07, Eric Blake wrote:
> [adding bug-tar]
> 
> On 03/07/2011 07:43 AM, Corinna Vinschen wrote:
> > THis looks like a tar bug, per the strace.  For some reason, if the
> > file is empty, tar calls futimens on file descriptor 0 (which is
> > connected to /dev/tty1 in my case), while it call futimens on
> > file descriptor 4 (connected to the file empty) if the file empty
> > is... well, not empty.
> 
> This is indeed multiple bug reports for the price of 1 :)
> [...]
> Finally, cygwin is failing with EINVAL for futimens on a pty fd.
> However, I don't know if that's something that we can change, since
> cygwin doesn't really maintain a notion of changeable times on ptys at
> the moment.

Please take this as granted for now.  Ptys/ttys are implemented using
other Windows objects (events, pipes, etc) and none of them supports
setting a file time.  I don't know if faking the ability to set the
filetime is really feasible.

Maybe we should just return EPERM?


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat

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