How to chown when a user name contains a dash?

Question

A user and group contains a dash: abc-def. When I try to use chown I get an error:

chown abc-def.abc-def * -R
chown: invalid user: `abc-def.abc-def'

the user is valid and it should work... how can I use chown with user/group names containing a dash?

Answer 1

GNU chown uses a colon instead now to separate user and group.

chown abc-def:abc-def * -R