How do I make there be no group owner of a file in Mac OSX?

Question

How do I make there be no group owner of a file in Mac OSX, since

chgrp nogroup file

doesn't work? If I try, the group owner doesn't change at all.

Answer 1

Use chgrp nobody file instead.

Answer 2

You can't. Every file has to have an owner and a group.

There is, however, a common convention of having a user called nobody (usually with uid 65534) and a group called either nobody or nogroup (usually with gid 65534).

e.g. on my debian systems, I have:

$ getent group nogroup
nogroup:x:65534:

$ getent passwd nobody
nobody:x:65534:65534:nobody:/nonexistent:/usr/sbin/nologin

if nogroup doesn't exist on your Mac, try chgrp nobody file instead.