NAME
groups - show group memberships

SYNOPSIS
groups [user]

DESCRIPTION
The groups command shows the groups to which you or the optionally
specified user belong. Each user belongs to a group specified in
the password file /etc/passwd and possibly to other groups as
specified in the file /etc/group. If you do not own a file but
belong to the group which it is owned by then you are granted group
access to the file.

When a new file is created it is given the group of the containing
directory.

SEE ALSO
setgroups(2)

FILES
/etc/passwd, /etc/group

BUGS
More groups should be allowed.