groups - print the groups a user is in
groups [OPTION]... [USERNAME]...
Print group memberships for each USERNAME or, if no USERNAME is
specified, for the current process (which may differ if the groups
database has changed).
--help display this help and exit
output version information and exit
Written by David MacKenzie and James Youngman.
Report groups bugs to email@example.com
GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
General help using GNU software: <http://www.gnu.org/gethelp/>
Report groups translation bugs to <http://translationproject.org/team/>
Copyright © 2010 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
The full documentation for groups is maintained as a Texinfo manual.
If the info and groups programs are properly installed at your site,
info coreutils 'groups invocation'
should give you access to the complete manual.