|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|
|
NAME | SYNOPSIS | DESCRIPTION | OPTIONS | CONFIGURATION | FILES | CAVEATS | EXIT VALUES | SEE ALSO | COLOPHON |
|
|
|
GROUPADD(8) System Management Commands GROUPADD(8)
groupadd - create a new group
groupadd [OPTIONS] NEWGROUP
The groupadd command creates a new group account using the values
specified on the command line plus the default values from the
system. The new group will be entered into the system files as
needed.
Groupnames may contain only lower and upper case letters, digits,
underscores, or dashes. They can end with a dollar sign. Dashes
are not allowed at the beginning of the groupname. Fully numeric
groupnames and groupnames . or .. are also disallowed.
Groupnames may only be up to 32 characters long.
The options which apply to the groupadd command are:
-f, --force
This option causes the command to simply exit with success
status if the specified group already exists. When used with
-g, and the specified GID already exists, another (unique)
GID is chosen (i.e. -g is turned off).
-g, --gid GID
The numerical value of the group's ID. GID must be unique,
unless the -o option is used. The value must be non-negative.
The default is to use the smallest ID value greater than or
equal to GID_MIN and greater than every other group.
See also the -r option and the GID_MAX description.
-h, --help
Display help message and exit.
-K, --key KEY=VALUE
Overrides /etc/login.defs defaults (GID_MIN, GID_MAX and
others). Multiple -K options can be specified.
Example: -K GID_MIN=100 -K GID_MAX=499
Note: -K GID_MIN=10,GID_MAX=499 doesn't work yet.
-o, --non-unique
permits the creation of a group with an already used
numerical ID. As a result, for this GID, the mapping towards
group NEWGROUP may not be unique.
-p, --password PASSWORD
defines an initial password for the group account. PASSWORD
is expected to be encrypted, as returned by crypt (3).
Without this option, the group account will be locked and
with no password defined, i.e. a single exclamation mark in
the respective field of ths system account file /etc/group or
/etc/gshadow.
Note: This option is not recommended because the password (or
encrypted password) will be visible by users listing the
processes.
You should make sure the password respects the system's
password policy.
-r, --system
Create a system group.
The numeric identifiers of new system groups are chosen in
the SYS_GID_MIN-SYS_GID_MAX range, defined in login.defs,
instead of GID_MIN-GID_MAX.
-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.
-P, --prefix PREFIX_DIR
Apply changes to configuration files under the root
filesystem found under the directory PREFIX_DIR. This option
does not chroot and is intended for preparing a
cross-compilation target. Some limitations: NIS and LDAP
users/groups are not verified. PAM authentication is using
the host files. No SELINUX support.
-U, --users
A list of usernames to add as members of the group.
The default behavior (if the -g, -N, and -U options are not
specified) is defined by the USERGROUPS_ENAB variable in
/etc/login.defs.
The following configuration variables in /etc/login.defs change
the behavior of this tool:
GID_MAX (number), GID_MIN (number)
Range of group IDs used for the creation of regular groups by
useradd, groupadd, or newusers.
The default value for GID_MIN (resp. GID_MAX) is 1000 (resp.
60000).
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.
SYS_GID_MAX (number), SYS_GID_MIN (number)
Range of group IDs used for the creation of system groups by
useradd, groupadd, or newusers.
The default value for SYS_GID_MIN (resp. SYS_GID_MAX) is 101
(resp. GID_MIN-1).
/etc/group
Group account information.
/etc/gshadow
Secure group account information.
/etc/login.defs
Shadow password suite configuration.
You may not add a NIS or LDAP group. This must be performed on
the corresponding server.
If the groupname already exists in an external group database
such as NIS or LDAP, groupadd will deny the group creation
request.
The groupadd command exits with the following values:
0
success
2
invalid command syntax
3
invalid argument to option
4
GID is already used (when called without -o)
9
group name is already used
10
can't update group file
chfn(1), chsh(1), passwd(1), gpasswd(8), groupdel(8),
groupmod(8), login.defs(5), useradd(8), userdel(8), usermod(8).
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
⟨https://github.com/shadow-maint/shadow⟩ on 2024-06-15. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-13.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
shadow-utils 4.14.0 06/15/2024 GROUPADD(8)
Pages that refer to this page: gpasswd(1), homectl(1), chgpasswd(8), groupdel(8), groupmems(8), groupmod(8), useradd(8), userdel(8), usermod(8)
|
HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
|