Joerg Schilling writes:
> It seems that some people at Sun try to boycott this future option.
There is no "boycott."
I think you mean to say that you believe that the ARC members are
either deliberately or ignorantly _precluding_ the option of replacing
pax and other things by star in the future.
This is not true. We do understand the nature of this
incompatibility. We're not fools. And there is no attempt or intent
to preclude _any_ future project.
The nature of the incompatibility is that, when invoked as
/usr/bin/tar or /usr/bin/pax, the 'star' implementation will be forced
to adopt the command line behavior of those older tools, the file
formats, and the documented behaviors. That requirement for backward
compatibility extends even to the options and features that the author
of star dislikes, such as the older '-@' and the new '-/' option.
When invoked as 'star', the utility may do as it likes. It needn't
support anything the other existing utilities do. But when invoked as
/usr/bin/tar, that's when backward compatibility becomes important.
This will be a complicated undertaking with or without this case. For
example, if I do this:
% cd /tmp
% cp /etc/motd .
% star cf test.tar /tmp/motd
% star xf test.tar
then, besides spewing unwanted and incompatible text out to stderr,
star will also fail to extract that archive properly. It will instead
create a new subdirectory and write the file /tmp/tmp/motd. It does
this even when invoked as 'tar'. That's not the same as 'tar', which
would (correctly) overwrite /tmp/motd.
Furthermore, if I go on to do this:
% star cf test.tar /tmp/motd
then 'star' dies like this:
star: Will not overwrite non empty plain files in compat mode.
Obviously, /usr/bin/tar does not share that hesitation about
overwriting files. Scripts that may have been written _assuming_ that
overwrites are ok will thus fail.
These changes in behavior are not compatible, and if we were to
consider changing /usr/bin/tar, we'd need to fix this (and likely many
other hidden incompatibilities) as well.
I'd certainly like to see 'pax' removed from the system, but I don't
think it's a simple change at all.
--
James Carlson, Solaris Networking <james.d.carlson at sun.com>
Sun Microsystems / 1 Network Drive 71.232W Vox +1 781 442 2084
MS UBUR02-212 / Burlington MA 01803-2757 42.496N Fax +1 781 442 1677
