Usage of "restore"

[Polytropon]

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

Eáu còntrair! :-)

     -f file
             Write the backup to file; file may be a special device file like
             /dev/sa0 (a tape drive), /dev/fd1 (a floppy disk drive), an ordi-
             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 dump
             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 at 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'Bäume 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 != .dump and != 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? :-)
> 
> No /bin/bash,
> 
> # ls /usr/local/bin/bash
> /usr/local/bin/bash
> 
> I run "bash file" instead of "sh file", IIRC I already had an issue when  
> 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,  
> if I continue writing this script or if I should write another script.  

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.




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