USERMOD

OPZIONI

The options which apply to the usermod command are:

-a, --append

Add the user to the supplementary group(s). Use only with the -G option.

-b, --badnames

Allow names that do not conform to standards.

-c, --comment COMMENT

The new value of the user's password file comment field. It is normally modified using the chfn(1) utility.

-d, --home HOME_DIR

La nuova directory home dell'utente.

If the -m option is given, the contents of the current home directory will be moved to the new home directory, which is created if it does not already exist. If the current home directory does not exist the new home directory will not be created.

-e, --expiredate EXPIRE_DATE

The date on which the user account will be disabled. The date is specified in the format YYYY-MM-DD.

An empty EXPIRE_DATE argument will disable the expiration of the account.

This option requires a /etc/shadow file. A /etc/shadow entry will be created if there were none.

-f, --inactive INACTIVE

Il numero di giorni dopo la scadenza di una password prima che l'account venga disabilitato permanentemente.

Il valore 0 disabilita l'account non appena la password è scaduta, e il valore -1 disabilita questa funzionalità.

This option requires a /etc/shadow file. A /etc/shadow entry will be created if there were none.

-g, --gid GROUP

Il nome o numero del gruppo da assegnare alla connessione dell'utente. Il gruppo deve esistere.

Tutti i file nella directory home dell'utente che hanno come gruppo il precedente gruppo primario dell'utente stesso verranno modificati perché abbiano questo nuovo gruppo.

Il gruppo dei file che si trovano all'esterno della directory home dell'utente andrà modificato manualmente.

The change of the group ownership of files inside of the user's home directory is also not done if the home dir owner uid is different from the current or new user id. This is safety measure for special home directories such as /.

-G, --groups GROUP1[,GROUP2,...[,GROUPN]]]

A list of supplementary groups which the user is also a member of. Each group is separated from the next by a comma, with no intervening whitespace. The groups are subject to the same restrictions as the group given with the -g option.

If the user is currently a member of a group which is not listed, the user will be removed from the group. This behaviour can be changed via the -a option, which appends the user to the current supplementary group list.

-l, --login NEW_LOGIN

The name of the user will be changed from LOGIN to NEW_LOGIN. Nothing else is changed. In particular, the user's home directory or mail spool should probably be renamed manually to reflect the new login name.

-L, --lock

Lock a user's password. This puts a '!' in front of the encrypted password, effectively disabling the password. You can't use this option with -p or -U.

Note: if you wish to lock the account (not only access with a password), you should also set the EXPIRE_DATE to 1.

-m, --move-home

Move the content of the user's home directory to the new location. If the current home directory does not exist the new home directory will not be created.

This option is only valid in combination with the -d (or --home) option.

usermod will try to adapt the ownership of the files and to copy the modes, ACL and extended attributes, but manual changes might be needed afterwards.

-o, --non-unique

When used with the -u option, this option allows to change the user ID to a non-unique value.

-p, --password PASSWORD

The encrypted password, as returned by crypt(3).

Note: This option is not recommended because the password (or encrypted password) will be visible by users listing the processes.

Ci si deve accertare che la password rispetti le norme delle password del sistema.

-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.

-s, --shell SHELL

Il nome della nuova shell di login dell'utente. Lasciando questo campo vuoto si fa in modo che il sistema selezioni la shell di login predefinita.

-u, --uid UID

Il nuovo valore numerico dell'ID utente.

This value must be unique, unless the -o option is used. The value must be non-negative.

La casella di posta dell'utente e ogni altro file di proprietà dell'utente che si trovi all'interno della directory home avrà l'ID utente cambiato automaticamente.

La proprietà dei file esterni alla directory home dell'utente va corretta manualmente.

The change of the user ownership of files inside of the user's home directory is also not done if the home dir owner uid is different from the current or new user id. This is safety measure for special home directories such as /.

No checks will be performed with regard to the UID_MIN, UID_MAX, SYS_UID_MIN, or SYS_UID_MAX from /etc/login.defs.

-U, --unlock

Unlock a user's password. This removes the '!' in front of the encrypted password. You can't use this option with -p or -L.

Note: if you wish to unlock the account (not only access with a password), you should also set the EXPIRE_DATE (for example to 99999, or to the EXPIRE value from /etc/default/useradd).

-v, --add-subuids FIRST-LAST

Add a range of subordinate uids to the user's account.

This option may be specified multiple times to add multiple ranges to a users account.

No checks will be performed with regard to SUB_UID_MIN, SUB_UID_MAX, or SUB_UID_COUNT from /etc/login.defs.

-V, --del-subuids FIRST-LAST

Remove a range of subordinate uids from the user's account.

This option may be specified multiple times to remove multiple ranges to a users account. When both --del-subuids and --add-subuids are specified, the removal of all subordinate uid ranges happens before any subordinate uid range is added.

No checks will be performed with regard to SUB_UID_MIN, SUB_UID_MAX, or SUB_UID_COUNT from /etc/login.defs.

-w, --add-subgids FIRST-LAST

Add a range of subordinate gids to the user's account.

This option may be specified multiple times to add multiple ranges to a users account.

No checks will be performed with regard to SUB_GID_MIN, SUB_GID_MAX, or SUB_GID_COUNT from /etc/login.defs.

-W, --del-subgids FIRST-LAST

Remove a range of subordinate gids from the user's account.

This option may be specified multiple times to remove multiple ranges to a users account. When both --del-subgids and --add-subgids are specified, the removal of all subordinate gid ranges happens before any subordinate gid range is added.

No checks will be performed with regard to SUB_GID_MIN, SUB_GID_MAX, or SUB_GID_COUNT from /etc/login.defs.

-Z, --selinux-user SEUSER

Il nuovo utente SELinux per il login dell'utente.

A blank SEUSER will remove the SELinux user mapping for user LOGIN (if any).

AVVISI/CAVEAT

You must make certain that the named user is not executing any processes when this command is being executed if the user's numerical user ID, the user's name, or the user's home directory is being changed. usermod checks this on Linux. On other platforms it only uses utmp to check if the user is logged in.

You must change the owner of any crontab files or at jobs manually.

Si devono apportare tutte le modifiche che riguardano NIS sul server NIS.  

CONFIGURAZIONE

The following configuration variables in /etc/login.defs change the behavior of this tool:

LASTLOG_UID_MAX (number)

Highest user ID number for which the lastlog entries should be updated. As higher user IDs are usually tracked by remote user identity and authentication services there is no need to create a huge sparse lastlog file for them.

No LASTLOG_UID_MAX option present in the configuration means that there is no user ID limit for writing lastlog entries.

MAIL_DIR (string)

La directory di spool per la posta. Questa è necessaria per manipolare la casella di posta quando il corrispondente account utente viene modificato o cancellato. Se non è specificata viene utilizzato un valore impostato al momento della compilazione.

MAIL_FILE (string)

Imposta la posizione delle caselle di posta degli utenti relative alla loro directory home.

The MAIL_DIR and MAIL_FILE variables are used by useradd, usermod, and userdel to create, move, or delete the user's mail spool.

If MAIL_CHECK_ENAB is set to yes, they are also used to define the MAIL environment variable.

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).

Il valore predefinito è 0, che non pone nessun limite al numero di membri per gruppo.

Questa opzione (dividi gruppo) permette di limitare la lunghezza delle righe nel file «group». Questo è utile per essere certi che le righe per gruppi NIS non eccedano i 1024 caratteri.

Se si deve impostare questo limite, si può usare 25.

Nota: la divisione dei gruppi potrebbe non essere supportata da ogni strumento (anche all'interno del pacchetto Shadow). Non si dovrebbe utilizzare questa variabile a meno di esserci forzati.

SUB_GID_MIN (number), SUB_GID_MAX (number), SUB_GID_COUNT (number)

If /etc/subuid exists, the commands useradd and newusers (unless the user already have subordinate group IDs) allocate SUB_GID_COUNT unused group IDs from the range SUB_GID_MIN to SUB_GID_MAX for each new user.

The default values for SUB_GID_MIN, SUB_GID_MAX, SUB_GID_COUNT are respectively 100000, 600100000 and 65536.

SUB_UID_MIN (number), SUB_UID_MAX (number), SUB_UID_COUNT (number)

If /etc/subuid exists, the commands useradd and newusers (unless the user already have subordinate user IDs) allocate SUB_UID_COUNT unused user IDs from the range SUB_UID_MIN to SUB_UID_MAX for each new user.

The default values for SUB_UID_MIN, SUB_UID_MAX, SUB_UID_COUNT are respectively 100000, 600100000 and 65536.

FILE

/etc/group

Informazioni sugli account di gruppo.

/etc/gshadow

Informazioni sicure sugli account di gruppo.

/etc/login.defs

Configurazione del pacchetto password shadow

/etc/passwd

Informazioni sugli account utente.

/etc/shadow

Informazioni sicure sugli account utente.

/etc/subgid

Per user subordinate group IDs.

/etc/subuid

Per user subordinate user IDs.

VEDERE ANCHE

chfn(1), chsh(1), passwd(1), crypt(3), gpasswd(8), groupadd(8), groupdel(8), groupmod(8), login.defs(5), subgid(5), subuid(5), useradd(8), userdel(8).