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Date:      Mon, 28 Jan 2013 17:38:58 +0100
From:      Polytropon <freebsd@edvax.de>
To:        "Ralf Mardorf" <ralf.mardorf@rocketmail.com>
Cc:        FreeBSD quest <freebsd-questions@freebsd.org>
Subject:   Re: Usage of "restore"
Message-ID:  <20130128173858.a39a3305.freebsd@edvax.de>
In-Reply-To: <op.wrmqo8k3uwjkcr@freebsd>
References:  <op.wrmmbb2cqhadp0@freebsd> <20130128165429.c5368afe.freebsd@edvax.de> <op.wrmqo8k3uwjkcr@freebsd>

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On Mon, 28 Jan 2013 17:28:10 +0100, Ralf Mardorf wrote:
> On Mon, 28 Jan 2013 16:54:29 +0100, Polytropon <freebsd@edvax.de> wrote:
> > The answer is in "man restore". :-)
>=20
> No it isn't ;). I did read it.

E=E1u c=F2ntrair! :-)

     -f file
             Write the backup to file; file may be a special device file li=
ke
             /dev/sa0 (a tape drive), /dev/fd1 (a floppy disk drive), an or=
di-
             nary file, or `-' (the standard output).  Multiple file names =
may
             be given as a single argument separated by commas.  Each file
             will be used for one dump volume in the order listed; if the d=
ump
             requires more volumes than the number of names given, the last
             file name will used for all remaining volumes after prompting =
for
             media changes.  If the name of the file is of the form
             ``host:file'', or ``user@host:file'', dump writes to the named
             file on the remote host using rmt(8).  The default path name of
             the remote rmt(8) program is /etc/rmt; this can be overridden =
by
             the environment variable RMT.

You could even set $TAPE to the file name and omit -f. :-)



> This was a Wald'n'B=E4ume situation.

That's possible.



> Even if I would have add a .bz2, I
> would have missed it, since on Linux I .tar.bz backups and it's more
> automated to extract a .tar.foo.

But .tar.bz !=3D .dump and !=3D dump.bz (different programs: tar and
dump are working differently).



> However, I should add .bz2 in the future.

At least this is a comfortable way to avoid confusion and know
file content by simply looking at its name.



> > Ern... two things: Do you _really_ have /bin/bash on FreeBSD?
> > I know this is possible.
> >
> > And do you use any bash-specific features in your script? If
> > not, why not use /bin/sh, the "universally" accepted standard? :-)
>=20
> No /bin/bash,
>=20
> # ls /usr/local/bin/bash
> /usr/local/bin/bash
>=20
> I run "bash file" instead of "sh file", IIRC I already had an issue when =
=20
> writing a script and running "sh file".

Okay, that is a fully valid solution, in that case #!/bin/bash
is ignored.

But just think about a "typical" worst case scenario: You
have a script that requires bash, and you need to apply it
it SUM with /usr unmounted, and you accidentally do not have
a statically linked /bin/bash. Wouldn't it be much more
convenient to rely on the /bin/sh default scripting shell?

Maybe if you review your script, you can find out what
bash-ism is employed and turn it into a valid sh equivalent
while keeping the intended functionality. At a first glance,
I don't see anything sh can't do.



> I use it, since I use it on Linux too, another shell might cause issues, =
=20
> if I continue writing this script or if I should write another script. =20

Interoperability for scripting is hard in regards of Linux,
where sh isn't bash, and sometimes bash isn't bash either. :-)



> I thought /bin/sh is a link to another shell.

Sometimes it is. Sometimes not.

-r-xr-xr-x  1 root  wheel  115348 2011-08-21 20:23:20 /bin/sh*

On FreeBSD, /bin/sh is technically ash ("This code is derived
from software contributed to Berkeley by Kenneth Almquist.",
see /usr/src/bin/sh/main.c), a replacement for the traditional
Bourne shell whose name it inherits. It's a real binary, not
a link.




--=20
Polytropon
Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...



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