-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On Tue, 23 Jul 2002, Peter Cornelius wrote:

> As a Mandrake newbie from Saturday I believe the first thing I need to do
> is to come to terms with some of the new expressions, commands and
> abbreviations. I was advised from whence to download some documentation.
> The downloaded file came with a .gz extension, which had I the
> documentation (!) might have told me was a zip file.

A .gz is not, in an of itself, an archive in the same way a zip file is.
It's simply a compressed file, in that case using gzip. The same is true
of files ending in ".bz2", in that case bzip2 (again.. just compression).

In many cases, the "archive" part will be a tar. So you need two tools to
unpack a file with a ".tar.gz" extension - g[un]zip and tar. Thankfully,
recent versions of GNU tar has gzip support, using the z switch. If it was
a .bz2, then you'd have to involve both tools.

For example, if I have the file "mystuff.tar.gz", I use:

 tar zxvf mystuff.tar.gz 

to decompress and unpack the contents. That only works with GNU tar,
whereas:

 gzip -cd mystuff.tar.gz | tar xvf - 

works on any *nix. In this case, I'm decompressing the file (-d on gzip or
I could use gunzip instead and skip the -d), piping the resulting
decompressed output into tar (-c tells gzip to output to stdout, the pipe
charater connects stdout to stdin of tar), and telling tar to extract it
(x for extract, v for verbose, f for file, and the filename is "-", which
means stdin).

If it was a .bz2 file, you'd have to do a similar thing, since only very
new versions of GNU tar support bz2 internally:

 bzip2 -cd mystuff.tar.bz2 | tar xvf -

If they do, you can reduce this down to:

 tar jxvf mystuff.tar.bz2

but the net effect is the same. 

Clear as mud? Happy to clarify anything. 

- -- 
"I know of no technological device at this time that would [prevent
priracy] and if it did exist, it would only be a matter of days before the
[..] manufacturers would have an override piece of equipment on their
machine and you would start from ground zero again."
   -- Jack Valenti, President of the MPAA (1982)
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.6 (GNU/Linux)
Comment: Made with pgp4pine 1.75-6

iD8DBQE9PK+DT21+qRy4P+QRArh0AKDu49zQdvDC0iolkvxlvOyyz3AEkACfRqH7
SM/ctHvdf45ek/aXDZ4Qqc0=
=czQJ
-----END PGP SIGNATURE-----


Reply via email to