groupmems(8) — Linux manual page
GROUPMEMS(8) System Management Commands GROUPMEMS(8)
NAME
groupmems - administer members of a user's primary group
SYNOPSIS
groupmems -a user_name | -d user_name | [-g group_name] | -l | -p
DESCRIPTION
The groupmems command allows a user to administer their own group
membership list without the requirement of superuser privileges.
The groupmems utility is for systems that configure its users to
be in their own name sake primary group (i.e., guest / guest).
Only the superuser, as administrator, can use groupmems to alter
the memberships of other groups.
OPTIONS
The options which apply to the groupmems command are:
-a, --add user_name
Add a user to the group membership list.
If the /etc/gshadow file exist, and the group has no entry in
the /etc/gshadow file, a new entry will be created.
-d, --delete user_name
Delete a user from the group membership list.
If the /etc/gshadow file exist, the user will be removed from
the list of members and administrators of the group.
If the /etc/gshadow file exist, and the group has no entry in
the /etc/gshadow file, a new entry will be created.
-g, --group group_name
The superuser can specify which group membership list to
modify.
-h, --help
Display help message and exit.
-l, --list
List the group membership list.
-p, --purge
Purge all users from the group membership list.
If the /etc/gshadow file exist, and the group has no entry in
the /etc/gshadow file, a new entry will be created.
-R, --root CHROOT_DIR
Apply changes in the CHROOT_DIR directory and use the
configuration files from the CHROOT_DIR directory. Only
absolute paths are supported.
SETUP
The groupmems executable should be in mode 2710 as user root and
in group groups. The system administrator can add users to group
groups to allow or disallow them using the groupmems utility to
manage their own group membership list.
$ groupadd -r groups
$ chmod 2710 groupmems
$ chown root:groups groupmems
$ groupmems -g groups -a gk4
CONFIGURATION
The following configuration variables in /etc/login.defs change
the behavior of this tool:
MAX_MEMBERS_PER_GROUP (number)
Maximum members per group entry. When the maximum is reached,
a new group entry (line) is started in /etc/group (with the
same name, same password, and same GID).
The default value is 0, meaning that there are no limits in
the number of members in a group.
This feature (split group) permits to limit the length of
lines in the group file. This is useful to make sure that
lines for NIS groups are not larger than 1024 characters.
If you need to enforce such limit, you can use 25.
Note: split groups may not be supported by all tools (even in
the Shadow toolsuite). You should not use this variable
unless you really need it.
FILES
/etc/group
Group account information.
/etc/gshadow
secure group account information
SEE ALSO
chfn(1), chsh(1), passwd(1), groupadd(8), groupdel(8),
useradd(8), userdel(8), usermod(8).
COLOPHON
This page is part of the shadow-utils (utilities for managing
accounts and shadow password files) project. Information about
the project can be found at
⟨https://github.com/shadow-maint/shadow⟩. If you have a bug
report for this manual page, send it to
pkg-shadow-devel@alioth-lists.debian.net. This page was obtained
from the project's upstream Git repository
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