groups —
show group memberships
The groups utility has been obsoleted by
the
id(1) utility, and is equivalent to
“id -Gn
[user]”. The command
“id -p” is
suggested for normal interactive use.
The groups utility displays the groups to
which you (or the optionally specified user)
belong.
The groups utility exits 0 on
success, and >0 if an error occurs.
Show groups the root user belongs to:
$ groups root
wheel operator