From owner-freebsd-questions@freebsd.org  Sun Jun 18 20:37:24 2017
Return-Path: <owner-freebsd-questions@freebsd.org>
Delivered-To: freebsd-questions@mailman.ysv.freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
 [IPv6:2001:1900:2254:206a::19:1])
 by mailman.ysv.freebsd.org (Postfix) with ESMTP id CDE4AD8D806
 for <freebsd-questions@mailman.ysv.freebsd.org>;
 Sun, 18 Jun 2017 20:37:24 +0000 (UTC)
 (envelope-from dpchrist@holgerdanske.com)
Received: from holgerdanske.com (holgerdanske.com
 [IPv6:2001:470:0:19b::b869:801b])
 (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits))
 (Client CN "holgerdanske.com", Issuer "holgerdanske.com" (not verified))
 by mx1.freebsd.org (Postfix) with ESMTPS id BDDF47B219
 for <freebsd-questions@freebsd.org>; Sun, 18 Jun 2017 20:37:24 +0000 (UTC)
 (envelope-from dpchrist@holgerdanske.com)
Received: from 99.100.19.101 ([99.100.19.101]) by holgerdanske.com with ESMTPSA
 (ECDHE-RSA-AES128-GCM-SHA256:TLSv1.2:Kx=ECDH:Au=RSA:Enc=AESGCM(128):Mac=AEAD)
 (SMTP-AUTH username dpchrist@holgerdanske.com, mechanism PLAIN)
 for <freebsd-questions@freebsd.org>; Sun, 18 Jun 2017 13:37:23 -0700
From: David Christensen <dpchrist@holgerdanske.com>
Subject: Re: tar: Failed to open '/dev/sa0'
To: freebsd-questions@freebsd.org
References: <9369978e-7041-3ef9-2cb4-66555054425b@holgerdanske.com>
 <9fa11efc8dc815b02b53565e468c7eb6@perso.pw>
Message-ID: <a1b0e753-6ad1-5425-e41e-a6350c746b7c@holgerdanske.com>
Date: Sun, 18 Jun 2017 13:37:22 -0700
User-Agent: Mozilla/5.0 (X11; FreeBSD i386; rv:45.0) Gecko/20100101
 Thunderbird/45.6.0
MIME-Version: 1.0
In-Reply-To: <9fa11efc8dc815b02b53565e468c7eb6@perso.pw>
Content-Type: text/plain; charset=windows-1252; format=flowed
Content-Transfer-Encoding: 8bit
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.23
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions/>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
 <mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Sun, 18 Jun 2017 20:37:24 -0000

On 06/18/17 13:21, Solène Rapenne wrote:
> Je 2017-06-18 20:59, David Christensen skribis:
>> 2017-06-18 11:53:14 dpchrist@freebsd ~
>> $ tar c .thunderbird > dpchrist-thunderbird-20170618.tar
>> tar: Failed to open '/dev/sa0'
> I think the syntax should be
>
> tar cf - .thunderbird > output.tar
>
> or
>
> tar cf output.tar .thunderbird
>
> /dev/sd0 is a tape device IIRC, tar assume you want to save to a tape
> by default, that's why you have to use the f flag (to a file or to
> standard output)

Yes -- thank you:

2017-06-18 13:31:20 dpchrist@freebsd ~
$ tar cf - .thunderbird > output.tar

2017-06-18 13:31:37 dpchrist@freebsd ~
$ gtar cf - .thunderbird > output.gtar

2017-06-18 13:31:52 dpchrist@freebsd ~
$ ls -l output.*
-rw-r--r--  1 dpchrist  dpchrist  223703040 Jun 18 13:31 output.gtar
-rw-r--r--  1 dpchrist  dpchrist  223119360 Jun 18 13:31 output.tar


I STFW yesterday, found that solution, and thought I had tried it.  But, 
the tar command is issued over SSH by a Perl script running on another 
machine with the output piped to that other machine, so I must have 
confused myself with too many levels of indirection....


David