Re: [Bug-tar] Re: AMTAR brokenness

[Alexandre Duret-Lutz]

>>> "Paul" == Paul Eggert <address@hidden> writes:

 Paul> Alexandre Duret-Lutz <address@hidden> writes:
 >> 1. The --format=posix options is a GNU Tar option, which means `make dist'
 >> can no longer be run with other make implementations.

 Paul> Presumably you meant "tar implementations" and not "make
 Paul> implementations"?  

Yep.

 Paul> But this is already the case, as the existing code uses
 Paul> the -o option, which is specific to GNU tar (the -o
 Paul> option has a different meaning with traditional tar, and
 Paul> traditional tar rejects -o when creating archives).

Thanks, I didn't know that.  My comment was only based on the
fact that the automake test suite uses it and nobody ever
complained about it.  But of course the test suite doesn't
verify the output format.

Looking into why I never noticed myself, I can see that

  Solaris 8's tar ignores `o' when creating archives (I guess it
  create a ustar file, though I do not know how to verify this).

  FreeBSD/NetBSD/OpenBSD/Darwin's tar understand `o' as a V7 request 
  like GNU Tar.

  OSF1's tar understand's `o' as GNU tar does when creating archives,
  and as Solaris does when extracting archives.

I cannot check more platform.  But at least it's interesting
that it works on more that just GNU tar.

 >> Forcing the ustar format might be a possibility (is it?), if
 >> that can be done portably (that probably involves a configure
 >> check).

 Paul> Yes, I think this is the best approach: that is, use --format=ustar if
 Paul> available, then -o if that works, otherwise don't use anything.

 >> Another idea is to arrange the dist rules so users have
 >> a way to override the tar options.

 Paul> That also might be helpful, though I think not as useful; most users
 Paul> won't want to futz with this.

Ok.  I'll try to do both of these this week-end and Cc the patch
to bug-tar for comments.
-- 
Alexandre Duret-Lutz