POSIX, NFS, CPIO/TAR

[Dominick Samperi]

Has anyone noticed that the NFS convention of returning uid/gid=-2/-2 (user
nobody) under certain circumstances results in a corrupted CPIO dump (due
to sign extension, on a Sun3, for example). I imagine that other UNIX
utilities are written with the assumption uid >= 0, gid >=0 as well.
(This only happens when the CPIO "portability" option, -c, is used.)

This happens, for example, when files in a VMS file system are mounted on
a UNIX machine, and there is no proxy mapping for the files on the VMS
side. This does not appear to be simply another VMS bug, since Sun
ships /etc/passwd with a nobody entry, uid/gid=-2/-2.

Does the POSIX standard (or any other evolving standard) address this
issue? Where can one find these standards documented, particularly the
CPIO/TAR standards?
-- 
Dominick Samperi -- Citicorp
dsamperi at Citicorp.COM
uunet!ccorp!dsamperi