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Date:	Mon, 7 Mar 2011 10:54:39 -0500
From:	Christopher Faylor <cgf-use-the-mailinglist-please AT cygwin DOT com>
To:	cygwin AT cygwin DOT com
Subject:	Re: tar --atime-preserve with an empty file triggers a warning
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On Mon, Mar 07, 2011 at 04:43:30PM +0100, Corinna Vinschen wrote:
>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?

Someday we really should implement something like devfs.

cgf

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