Subject: Re: FYI: upgrading GNU tar
To: None <>
From: Greg A. Woods <>
List: current-users
Date: 10/11/2002 18:05:51
[ On Friday, October 11, 2002 at 15:13:48 (-0600), Rick Kelly wrote: ]
> Subject: Re: FYI: upgrading GNU tar
> Greg A. Woods said:
> > 
> > Really?  Archives with standard "ustar" encoding?  I'd be very surprised
> > if that were true.  I haven't had any problems myself, nor have I heard
> > from anyone I've ever created archives for.  Sun claims (at least ever
> > since SunOS-5.6, up to and including SunOS-5.9) that their 'pax -x
> > ustar' can extract any archive compliant with IEEE 1003.1(1990).  They
> > also support 'xustar' in at least SunOS-5.9, which allows larger UID,
> > GID, dev, etc. values and which supports 64-bit file offsets and
> > pathnames greater than 255 chars.
> Actually, I mean straight pax archives.

In other words the default IEEE POSIX Standard "ustar" format archives.

> NetBSD has some flags that would
> create pax archives that Solaris can't read.

I think it's time to break out some examples if you can think of any.
I've never heard of this.

Are you sure you're not thinking about the '-x' option flag?

(I currently still have access to both SunOS-5.6 and SunOS-5.9 for

> If pax works with all tar archives, then that's fine.

It's pretty hard to make a blanket statement like that for any
implementation of a program that reads "tar archives".  GNU Tar won't
read archives produced by some more rare implementations (certianly not
the version "we" had, though the latest release tries a lot harder), and
the same goes for every vendor implementation based on the original code.

There is one minor annoyance with 'pax' at the moment when using its
native command-line interface in that it needs '-O' to not be noisily
interactive when reading archives created by some other implementations.
However that's not a problem with it's 'tar' command-line interface as
the "Right Thing" is done in that case.

I haven't ever encountered any tar archives on the net that cause me any
grief with 'pax', though I can't claim to have unpacked even all those
used in pkgsrc (${GTAR} is defined in pkgsrc, but I don't immediately
see any use of it in any of the makefiles I have, and I have had
EXTRACT_USING_PAX defined for quite a long time now and I've patched the
related _DFLT_EXTRACT_CMD to use 'pax -O' instead of 'dd | pax' too).

> If someone puts in
> rmt support then there is no reason that it couldn't replace the current
> NetBSD/gnutar.

It seems Christos has implemented 'rmt' support already!  ;-)

								Greg A. Woods

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