создать новую группу (create a new group)
Имя (Name)
groupadd - create a new group
Синопсис (Synopsis)
groupadd [options] group
Описание (Description)
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.
Параметры (Options)
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. 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 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
This option permits to add a group with a non-unique GID.
-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 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.
-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.
-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.
Конфигурация (Configuration)
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).
Файлы (Files)
/etc/group
Group account information.
/etc/gshadow
Secure group account information.
/etc/login.defs
Shadow password suite configuration.
Предостережение (Caveat)
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 16 characters long.
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.
Статус выхода (Exit)
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
Смотри также (See also)
chfn(1), chsh(1), passwd(1), gpasswd(8), groupdel(8),
groupmod(8), login.defs(5), useradd(8), userdel(8), usermod(8).
