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Date: Tue, 10 Feb 2015 09:33:29 -0700
From: Eric Blake <eblake AT redhat DOT com>
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To: cygwin AT cygwin DOT com
Subject: Re: /dev/tty does not work from shell
References: <1598899839 DOT 20150209072327 AT yandex DOT ru> <54D8741A DOT 5020805 AT towo DOT net> <20150209113620 DOT F876DF38 DOT helmut DOT karlowski AT ish DOT de> <54D91AC6 DOT 8030101 AT towo DOT net> <54D91E53 DOT 5080907 AT redhat DOT com> <54DA31C1 DOT 9060406 AT redhat DOT com>
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On 02/10/2015 09:28 AM, Eric Blake wrote:
>=20
> The bug is in cygwin1.dll, not bash.  Here's a STC; opening a file
> should NOT change its st_ino number, but that's exactly what cygwin is
> doing to /dev/tty.  As such, bash thinks that because the ino changed
> between stat() and open() that there is a race of someone trying to do
> bad things behind bash's back, and noclobber restrictions kick in to
> prevent bash from using the file.

The same test from the command line:

$ stat -c %i /dev/tty - 0>/dev/tty
327680
8912896

use any other (already-existing) file to see that the two numbers should
normally be the same.

--=20
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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