tl-memberof-group <groupname> [groupname…]
tl-memberof-group can be used to determine if the current user is a member of the specified groups.
The executing user is a member of any of the given groups.
The executing user is not a member of any of the groups.
One or more of the specified groups cannot be found.
Is user a member of the root group?
$ tl-memberof-group root
Is the user member of the sysadmin or techsupport groups?
$ tl-memberof-group sysadmin techsupport