groupadd - create a new group
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.
The options which apply to the groupadd command are:
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. This value 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
and greater than every other group.
See also the -r option and the GID_MAX
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_MIN=10,GID_MAX=499 doesn't
This option permits to add a group with a non-unique
-p, --password PASSWORD
The encrypted password, as returned by crypt(3)
The default is to disable the password.
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
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
-R, --root CHROOT_DIR
Apply changes in the CHROOT_DIR directory and use
the configuration files from the CHROOT_DIR directory.
-P, --prefix PREFIX_DIR
Apply changes in the PREFIX_DIR directory and use
the configuration files from the PREFIX_DIR directory. 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.
The following configuration variables in /etc/login.defs change the behavior of
GID_MAX (number), GID_MIN (number)
Range of group IDs used for the creation of regular
groups by useradd
, or newusers
The default value for GID_MIN (resp. GID_MAX) is
1000 (resp. 60000).
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
SYS_GID_MAX (number), SYS_GID_MIN (number)
Range of group IDs used for the creation of system groups
, or newusers
The default value for SYS_GID_MIN (resp.
SYS_GID_MAX) is 101 (resp. GID_MIN-1).
Group account information.
Secure group account information.
Shadow password suite configuration.
Groupnames must start with a lower case letter or an underscore, followed by
lower case letters, digits, underscores, or dashes. They can end with a dollar
sign. In regular expression terms: [a-z_][a-z0-9_-]*[$]?
Groupnames may only be up to 32 characters long.
You may not add a NIS or LDAP group. This must be performed on the
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:
invalid command syntax
invalid argument to option
GID not unique (when -o not used)
group name not unique
can't update group file