X-Recipient:	archive-cygwin AT delorie DOT com
DomainKey-Signature:	a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:subject:to:references:from:message-id:date
	:mime-version:in-reply-to:content-type; q=dns; s=default; b=R0N8
	2wKRHjZVnJQz0Wj7Is3w9f7PpDKLatW/2noS4comvuMM3fwUJvBXfG1EFfl1bbky
	O9rw07jXIG+2GDPkEznysnosp/54bVGsXXSuFdkPd8T/k04LK5iZ0i5GpjsjcUX/
	R5JlrdbGKdsJYm+HuPf3aj6QSXNOIn0HM/L3C/Y=
DKIM-Signature:	v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
	:list-unsubscribe:list-subscribe:list-archive:list-post
	:list-help:sender:subject:to:references:from:message-id:date
	:mime-version:in-reply-to:content-type; s=default; bh=tNvBKgtIQZ
	GpqVrzq3te+X/SOxo=; b=VJuTArOcZmlwmcZL5JR2wgZLuOQZRFr6dSWujUdMuE
	fsyQrJc+YMrRJm2z7PLknDL+xFNMgBVV01K9dmEjLfGBke15U/IQ8tZEJLxiNsB4
	/FIijUZ/VUqlMi0xX/BXnN6g/AyGwLwal/fGMU7IysB61pzvdtzF3jNXWWdQZCQC
	8=
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
Authentication-Results:	sourceware.org; auth=none
X-Virus-Found:	No
X-Spam-SWARE-Status:	No, score=-2.9 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=headed, Hx-languages-length:1677, states, WILL
X-HELO:	mx1.redhat.com
Subject:	Re: windows exit codes truncated to 1 Byte
To:	cygwin AT cygwin DOT com
References:	<1233154500 DOT 205789 DOT 1459429282664 DOT JavaMail DOT yahoo DOT ref AT mail DOT yahoo DOT com> <1233154500 DOT 205789 DOT 1459429282664 DOT JavaMail DOT yahoo AT mail DOT yahoo DOT com> <56FD268D DOT 4060904 AT gmx DOT de> <56FD413A DOT 9050502 AT redhat DOT com> <20160331185002 DOT GA3353 AT calimero DOT vinschen DOT de>
From:	Eric Blake <eblake AT redhat DOT com>
Openpgp:	url=http://people.redhat.com/eblake/eblake.gpg
Message-ID:	<56FD7349.70003@redhat.com>
Date:	Thu, 31 Mar 2016 12:58:17 -0600
User-Agent:	Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.7.1
MIME-Version:	1.0
In-Reply-To:	<20160331185002.GA3353@calimero.vinschen.de>
X-IsSubscribed:	yes

--6m4wq9jXSwBIfM9o9nohrrEHdc4J1BVRM
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable

On 03/31/2016 12:50 PM, Corinna Vinschen wrote:
> On Mar 31 09:24, Eric Blake wrote:
>> On 03/31/2016 07:30 AM, Bj=C3=B6rn Stabel wrote:
>>> Am 31.03.2016 um 15:01 schrieb Cristian:
>>>> I noted that exit codes returned by CMD and other apps (msiexec) are t=
runcated to 1 byte (0 .. 255).
>>
>> This matches Linux, but not POSIX.
>=20
> Why?  Does bash use waitid?

Not yet, but with the link I referred to below, the thought is that
eventually bash WILL use waitid(), based on the direction POSIX is
headed in.

> But...
>=20
>>> POSIX specifies that the lower 8 bits of the exit status be made
>>> available to the caller of wait/waitpid:
>>> http://pubs.opengroup.org/onlinepubs/9699919799/functions/wait.html
>>
>> Correct: wait() and waitpid() can only return 8 bits; but POSIX states
>> that waitid() MUST be able to access all 32-bits untruncated; this is
>> where Linux gets it wrong (Linux truncates during exit(), so waitid()
>> can only return 8 bits; other operating systems do NOT truncate during
>> exit, but preserve all 32 bits; if you use wait() or waitpid() you only
>> get 8 bits, but if you use waitid() you can see the full 32 bits).
>=20
> ...that only makes sense if we implement waitid at all.  SHTDI and all
> that...

Right - without waitid(), it's fairly obvious that cygwin isn't quite up
to POSIX compliance yet :)  And indeed, patches are welcome, if someone
who cares enough about more than 8 bits wants to step up and write it
(personally, I don't care enough as long as Linux is still truncating
early during exit()).

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


--6m4wq9jXSwBIfM9o9nohrrEHdc4J1BVRM
Content-Type: application/pgp-signature; name="signature.asc"
Content-Description: OpenPGP digital signature
Content-Disposition: attachment; filename="signature.asc"

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
Comment: Public key at http://people.redhat.com/eblake/eblake.gpg
Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/

iQEcBAEBCAAGBQJW/XNJAAoJEKeha0olJ0Nq2skH/25do+nIwHmRtAoIgw/c9Noy
vIGKbG19zczuiekDRHlFbg8Dy05eufE9Ptp8XlsEPgzkrSbRst9RDfPHrawJWh9y
SQs6VTOWICwz+f0kai1C5ar29VR3XUvptT5oqigmr87wn6U2pYVWqtF4RV6rVWxX
MiCLsbqyU16rSReSdn8BOdKQ80w4eC23ribicPQKS1lqgefzF9BSUxoJ2x0hJX1M
2Hh5wOG3ihGvhr8ohKjzWp7yaXHwcC0HNANL3Tqxqn8IgYb6HiHAPLxVZkKx6c+0
e09jUlomvZyFPxrXk+hF61MQ199pDp8LRyaIMz41tTqFjqY4+DkEULE7QPDRR74=
=lKRX
-----END PGP SIGNATURE-----

--6m4wq9jXSwBIfM9o9nohrrEHdc4J1BVRM--

- Raw text -