GROUPS(1) — Unix Programmer’s Manual
NAME
groups − show group memberships
SYNOPSIS
groups [ user ]
DESCRIPTION
The groups command shows the groups to which you or the specified user belong. Each user belongs to a group specified in the password file /etc/passwd. A user may also belong to other groups, as specified in the file /etc/group. If you do not own a particular file but do belong to the group that owns it, 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
FILES
/etc/passwd, /etc/group
BUGS
More groups should be allowed.
5 BSD — April 29, 1985