GROUPADD(8)

NOME
groupadd - Crea un nuovo gruppo

SINOSSI

groupadd [opzioni] group

DESCRIZIONE

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.

OPZIONI

Il comando groupadd accetta le seguenti opzioni:

-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
    Il valore numerico dell'identificatore (ID) del gruppo. Questo valore deve essere univoco, a meno che non venga usata l'opzione -o. Il valore deve essere non-negativo. La scelta predefinita è quella di usare il minimo valore di ID superiore a 999 e superiore a qualunque altro gruppo. Valori tra 0 e 999 sono tipicamente riservati per account di sistema.

-h, --help
    Mostra un messaggio di aiuto ed esce.

-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.

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.

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.

FILE

/etc/group
    Informazioni sugli account di gruppo.

/etc/gshadow
    Informazioni sicure sugli account di gruppo.

/etc/login.defs
    Shadow password suite configuration.

AVVISI/CAVEAT

It is usually recommended to only use groupnames that begin 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_-]*[$]?

On Debian, the only constraints are that groupnames must neither start with a dash ('-') nor contain a colon (':') or a whitespace (space:' ', end of line: '\n', tabulation: '\t', etc.).

Groupnames may only be up to 32 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.

VALORI RESTITUITI

The groupadd command exits with the following values:

0
    successo

2
    sintassi del comando errata

3
    invalid argument to option

4
    GID not unique (when -o not used)

9
    group name not unique

10
    non è possibile aggiornare il file group

VEDERE ANCHE

chfn(1), chsh(1), passwd(1), gpasswd(8), groupdel(8), groupmod(8), login.defs(5), useradd(8), userdel(8), usermod(8).