Star vs. Gtar WAS: Re: BitKeeper licence critic

Joerg Schilling schilling at fokus.gmd.de
Mon Mar 18 14:19:03 UTC 2002


>From: John Tapsell <tapselj0 at cs.man.ac.uk>
>  I'm working on replacements for all the gnu utilities, so I'd be grateful 
>if you fill in a few details, and give me some recomondations...

>> >AFAIK GNU tar makes POSIX compliant tars if you use the --posix
>> >option. I've done enough stuff with GNU tar, but GNU/Linux and
>> >GNU/Hurd are the only operating systems I use for real work.
>> Many GNU users have this wrong assumption, this is why I am more and more
>> angry with the people who wrote documentation tha makes users believe
>> untrue things about the GNU programs...


>  What would you say is wrong exactly?  Excuse me for my ignorance...
>And why is it not fully POSIX compliant?

First some pointers:

ftp://ftp.fokus.gmd.de/pub/unix/star/alpha for the latest star release
ftp://ftp.fokus.gmd.de/pub/unix/star/testscripts for some test archives
						 and scripts.

Then please read the file STARvsGNUTAR from the latest star distribution.

-	GNUtar has some options that violate the POSIX tar command line definitions.

-	GNUtar is not even compatible to POSIX 1990 if it comes to
	medium sizefilenames ( > 100 and <= 255)

-	GNUtar violates the basic tar format if it archives sparse files 	
	with more tan 4 holes.

Star is POSIX 2001 compliant and implements extended tar headers and inside
those extended headers it even supports ACLs (access control lists)
and file flags.

>  The trouble is that we are 'stuck' with backwards compatibility, and 
>forwards compatibility.  If we add features to programs, we then are no 
>longer compatible with everyone else (everyone else being other NIX's, and 
>people who don't use the latest-and-greatest)

Well GNUtar although younger than star is definitely not backward compatible
to star.

What are you interested in?


>  This is good in some peoples books - after all everyone seems to be against 
>'bloat'.  But for example I patched tar to auto detect compression - but it 
>was of course a hated feature... ;)

This is an old feature of star.
Jörg

 EMail:joerg at schily.isdn.cs.tu-berlin.de (home) Jörg Schilling D-13353 Berlin
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