NEW TAR

[n***@freebsd.org]

On Sat, 17 Jul 2004 10:37:28 -0700

* File format: bsdtar can read gtar files, including
long file names, long link names, and sparse files.
bsdtar can also read many other formats that gtar
does not support.

WoW! > shar format support
This is useful for ports committers:-). I wanted it!
Of course, I am using knu's sunshar. But...

[p***@freebsd.org]

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On Sat, Jul 16, 2004 at 10:37:28AM -0700, Tim Kientzle wrote:
+> By default, /usr/bin/tar is now a symlink pointing
+> to /usr/bin/bsdtar.

And I hope it will stay. Great work, thank you!

--=20
Pawel Jakub Dawidek http://www.FreeBSD.org
***@FreeBSD.org http://garage.freebsd.pl
FreeBSD committer Am I Evil? Yes, I Am!

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[a***@nagual.pp.ru]

* File format: bsdtar can read gtar files, including
long file names, long link names, and sparse files.
bsdtar can also read many other formats that gtar
does not support.

Addition:
bsdtar can't write sparse archives (Yet?).

[a***@nagual.pp.ru]

but they're not gtar-compatible. (The gtar
approach has a number of drawbacks. The primary
one being that on many systems it requires reading
the entire file twice, once to find holes and again
to actually archive the file. It is possible to
do both in one pass if you store the sparse file
data in a different fashion.)

I can't imagine the case when 2 passes are needed. Even if you have normal
file in the archive and specify -S only when extracting (it should work as
expected), only 1 pass is needed. Just stop on first '\0' and count them
until they finished, then do lseek (real case will be a bit harder to
implement because of block boundaries).

[w***@khavrinen.lcs.mit.edu]

I do not see, why it is important if the original file was sparse
at all or maybe in different places.

You've never run out of disk space as a result of a sparse file
becoming non-sparse?

-GAWollman

[i***@hetzner.co.za]

How does dump handle sparse files?

Dump handles fine sparse files.

Maybe I should have asked how does dump figure out that the files
are sparse and if it's any more intelligent than a 2 pass read (I
have no idea why 2 passes are required) or just blindly turning
successive zeros into a seek offset, is there anything preventing
BSD tar from doing the same?

Ian

--
Ian Freislich