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:message-id:date:from:mime-version:to:subject
	:references:in-reply-to:content-type; q=dns; s=default; b=DzaLMz
	wk7azBFaE2LzCDztCQIQEztkUIMX23JUxCVOB3YwGLDTbx2x/CQ5mtlzW8E3XMEU
	K5ao1V0nnAQZUc6dqdvsUbwZdEghtrA/WJq4aLp5tCJfD26GQZjD9+ctSBNxDwcb
	WZ8b2glVI5CBdmF1Jaxa3uI7/JjhSHVcztKeo=
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:message-id:date:from:mime-version:to:subject
	:references:in-reply-to:content-type; s=default; bh=7gtchs+jgIJo
	sG7wvNaFfCGLNS8=; b=W+/HgDBOEWDj3PAifavtzBDbW6f/Ufxo04KAHr8XwiF0
	kz3j2SBswJ24ewMa/fEvgZYYFCVJpKwPALUhjJlBjaFUy94rt3kLL2Zy/5w0jf5x
	nJrtx6TXbK8rz7Y0VKbNRT0yqC1N12CchQ9TOCYPkbJd4jcn5TXstSm4DI0NwRk=
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=-2.0 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2
X-HELO: mx1.redhat.com
Message-ID: <55355DA5.8070302@redhat.com>
Date: Mon, 20 Apr 2015 14:12:21 -0600
From: Eric Blake <eblake AT redhat DOT com>
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0
MIME-Version: 1.0
To: cygwin AT cygwin DOT com
Subject: Re: tar zxvf won't  work with Redhat generated compressed tar file
References: <COL130-W80F61D41DBC766A5C40206C2E00 AT phx DOT gbl>,<55354928 DOT 3090004 AT chunkz DOT net> <COL130-W660D1B575445ACD2340D61C2E00 AT phx DOT gbl>,<55354CD2 DOT 7060407 AT chunkz DOT net> <COL130-W944A76EC87FAC75AC6DC7BC2E00 AT phx DOT gbl> <2748d7b76a6248fb853de6541f2582c6 AT EX2013DAG-B DOT pavlovmedia DOT corp>
In-Reply-To: <2748d7b76a6248fb853de6541f2582c6@EX2013DAG-B.pavlovmedia.corp>
OpenPGP: url=http://people.redhat.com/eblake/eblake.gpg
Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="RCdnBQUXoLrWDNR60QoJEevlbPCavtF9k"
X-IsSubscribed: yes

--RCdnBQUXoLrWDNR60QoJEevlbPCavtF9k
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable

On 04/20/2015 01:10 PM, Joi L. Ellis wrote:
>=20
> Note that some flavors of tar don't have a very powerful compression libr=
ary, and some don't have one at all.  For those old ones you may be forced =
to use gunzip to get the tarball into a form the old tar understands.  (My =
ancient CentOS box has it, though.)

GNU tar does NOT use compression libraries; rather, it shells out (via
an equivalent to popen()) to an external program.  If you tell tar which
format a file was compressed in, it should try to use that compression
utility without questions; if you omit the compression format, tar knows
enough magic numbers to shell out to the most common default decompressors.

But one thing that MAY be happening is if a newer gzip is at play.
Upstream has reports of tar failing if $GZIP is set in the environment,
since newer gzip explicitly warns about this setup, and the warning may
interfere with tar's use of the output stream from the resulting
decompression:
https://lists.gnu.org/archive/html/bug-tar/2015-03/msg00006.html

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


--RCdnBQUXoLrWDNR60QoJEevlbPCavtF9k
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/

iQEcBAEBCAAGBQJVNV2lAAoJEKeha0olJ0Nq6tUH/ipJGbQGgm52dv0u3o+NjN4u
bYjSS6VvSHLCy1+fqV5CVwGL1v5mHI2lcZDrFMQkrQDwtTZrFKrHLsBTxW2izKQF
kUp38jVP2Lzu77nMNffeIXuuuwQ3ucbYgMgqH9blvQUbuuH85560mR0ybJpdzRhw
gaLmXJ/9tw7JtJDlINS5IEKu65eITDfoCF4S9fDFox+H6tL0xa4/2K2hvUhaDP3C
xqXpaiXxVuLDXd6n5TnDhCjn/SvpMHPcFqfVP3N4onEFqNACKk6dcySO1MS6v1rM
LWoGR0SFOuJidmJmPk9HI/lhs8I8GrU/7nq5NZmiQ2dihvsFW2euC/nIH7EPeU4=
=Vbs9
-----END PGP SIGNATURE-----

--RCdnBQUXoLrWDNR60QoJEevlbPCavtF9k--