USERADD(8)

NOM
useradd - créer un nouvel utilisateur ou modifier les informations par défaut appliquées aux nouveaux utilisateurs

SYNOPSIS

useradd [options] LOGIN

useradd -D

useradd -D [options]

DESCRIPTION

When invoked without the -D option, the useradd command creates a new user account using the values specified on the command line plus the default values from the system. Depending on command line options, the useradd command will update system files and may also create the new user's home directory and copy initial files.

By default, a group will also be created for the new user (see -g, -N, -U, and USERGROUPS_ENAB).

OPTIONS

The options which apply to the useradd command are:

--badname
    Allow names that do not conform to standards.

-b, --base-dir BASE_DIR
    The default base directory for the system if -d HOME_DIR is not specified. BASE_DIR is concatenated with the account name to define the home directory. If the -m option is not used, BASE_DIR must exist.

    If this option is not specified, useradd will use the base directory specified by the HOME variable in /etc/default/useradd, or /home by default.

-c, --comment COMMENT
    Toute chaîne de texte. C'est généralement une description courte du compte, elle est actuellement utilisée comme champ pour le nom complet de l'utilisateur.

-d, --home-dir HOME_DIR
    The new user will be created using HOME_DIR as the value for the user's login directory. The default is to append the LOGIN name to BASE_DIR and use that as the login directory name. If the directory HOME_DIR does not exist, then it will be created unless the -M option is specified.

-D, --defaults
    Consultez ci-dessous la sous-section « Modifier les valeurs par défaut ».

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

    If not specified, useradd will use the default expiry date specified by the EXPIRE variable in /etc/default/useradd, or an empty string (no expiry) by default.

-f, --inactive INACTIVE
    Nombre de jours suivant la fin de validité d'un mot de passe après lequel le compte est définitivement désactivé. Une valeur de 0 désactive le compte dès que le mot de passe a dépassé sa fin de validité, et une valeur de -1 désactive cette fonctionnalité.

    If not specified, useradd will use the default inactivity period specified by the INACTIVE variable in /etc/default/useradd, or -1 by default.

-g, --gid GROUP
    Nom du groupe ou identifiant numérique du groupe de connexion initial de l'utilisateur. Le nom du groupe doit exister. Un numéro de groupe doit se référer à un groupe déjà existant.

    If not specified, the behavior of useradd will depend on the USERGROUPS_ENAB variable in /etc/login.defs. If this variable is set to yes (or -U/--user-group is specified on the command line), a group will be created for the user, with the same name as her loginname. If the variable is set to no (or -N/--no-user-group is specified on the command line), useradd will set the primary group of the new user to the value specified by the GROUP variable in /etc/default/useradd, or 100 by default.

-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. The default is for the user to belong only to the initial group.

-h, --help
    Afficher un message d'aide et quitter.

-k, --skel SKEL_DIR
    The skeleton directory, which contains files and directories to be copied in the user's home directory, when the home directory is created by useradd.

    This option is only valid if the -m (or --create-home) option is specified.

    If this option is not set, the skeleton directory is defined by the SKEL variable in /etc/default/useradd or, by default, /etc/skel.

    Si possible, les ACL et les attributs étendus seront copiés.

-K, --key KEY=VALUE
    Overrides /etc/login.defs defaults (UID_MIN, UID_MAX, UMASK, PASS_MAX_DAYS and others). Example: -K PASS_MAX_DAYS=-1 can be used when creating system account to turn off password aging, even though system account has no password at all. Multiple -K options can be specified, e.g.: -K UID_MIN=100 -K UID_MAX=499

-l, --no-log-init
    N'ajoute pas l'utilisateur aux bases de données lastlog et faillog.

    Par défaut, les entrées de l'utilisateur dans les bases de données lastlog et faillog sont remises à zéro pour éviter de réutiliser les entrées d'un utilisateur précédemment supprimé.

-m, --create-home
    Create the user's home directory if it does not exist. The files and directories contained in the skeleton directory (which can be defined with the -k option) will be copied to the home directory.

    By default, if this option is not specified and CREATE_HOME is not enabled, no home directories are created.

    The directory where the user's home directory is created must exist and have proper SELinux context and permissions. Otherwise the user's home directory cannot be created or accessed.

-M, --no-create-home
    Do no create the user's home directory, even if the system wide setting from /etc/login.defs (CREATE_HOME) is set to yes.

-N, --no-user-group
    Do not create a group with the same name as the user, but add the user to the group specified by the -g option or by the GROUP variable in /etc/default/useradd.

    The default behavior (if the -g, -N, and -U options are not specified) is defined by the USERGROUPS_ENAB variable in /etc/login.defs.

-o, --non-unique
    Permet de créer un compte d'utilisateur avec un identifiant (« UID ») dupliqué (non unique).

    This option is only valid in combination with the -u option.

-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.

    Il est nécessaire de vérifier si le mot de passe respecte la politique de mots de passe du système.

-r, --system
    Créer un compte système.

    System users will be created with no aging information in /etc/shadow, and their numeric identifiers are chosen in the SYS_UID_MIN-SYS_UID_MAX range, defined in /etc/login.defs, instead of UID_MIN-UID_MAX (and their GID counterparts for the creation of groups).

    Note that useradd will not create a home directory for such a user, regardless of the default setting in /etc/login.defs (CREATE_HOME). You have to specify the -m options if you want a home directory for a system account to be created.

-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
    The name of the user's login shell. The default is to leave this field blank, which causes the system to select the default login shell specified by the SHELL variable in /etc/default/useradd, or an empty string by default.

-u, --uid UID
    The numerical value of the user'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 UID_MIN and greater than every other user.

    See also the -r option and the UID_MAX description.

-U, --user-group
    Crée un groupe avec le même nom que celui de l'utilisateur, et ajoute l'utilisateur à ce groupe.

    The default behavior (if the -g, -N, and -U options are not specified) is defined by the USERGROUPS_ENAB variable in /etc/login.defs.

-Z, --selinux-user SEUSER
    L'utilisateur SELinux utilisé pour la connexion de l'utilisateur. Le comportement par défaut est de laisser ce champ vide. Le système sélectionnera alors l'utilisateur SELinux par défaut.

  Modifier les valeurs par défaut

When invoked with only the -D option, useradd will display the current default values. When invoked with -D plus other options, useradd will update the default values for the specified options. Valid default-changing options are:

-b, --base-dir BASE_DIR
    The path prefix for a new user's home directory. The user's name will be affixed to the end of BASE_DIR to form the new user's home directory name, if the -d option is not used when creating a new account.

    This option sets the HOME variable in /etc/default/useradd.

-e, --expiredate EXPIRE_DATE
    Date à laquelle le compte utilisateur sera désactivé.

    This option sets the EXPIRE variable in /etc/default/useradd.

-f, --inactive INACTIVE
    Nombre de jours après la fin de validité d'un mot de passe avant que le compte ne soit désactivé.

    This option sets the INACTIVE variable in /etc/default/useradd.

-g, --gid GROUP
    The group name or ID for a new user's initial group (when the -N/--no-user-group is used or when the USERGROUPS_ENAB variable is set to no in /etc/login.defs). The named group must exist, and a numerical group ID must have an existing entry.

    This option sets the GROUP variable in /etc/default/useradd.

-s, --shell SHELL
    Le nom de l'interpréteur de commandes du nouvel utilisateur.

    This option sets the SHELL variable in /etc/default/useradd.

NOTES

The system administrator is responsible for placing the default user files in the /etc/skel/ directory (or any other skeleton directory specified in /etc/default/useradd or on the command line).

AVERTISSEMENTS

Vous ne pouvez pas ajouter d'utilisateur à un groupe NIS ou LDAP. Cela doit être effectué sur le serveur correspondant.

Similarly, if the username already exists in an external user database such as NIS or LDAP, useradd will deny the user account creation request.

Usernames 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 username. Fully numeric usernames and usernames . or .. are also disallowed. It is not recommended to use usernames beginning with . character as their home directories will be hidden in the ls output.

Les noms d'utilisateur sont limités à 16 caractères.

CONFIGURATION

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

FICHIERS

/etc/passwd
    Informations sur les comptes des utilisateurs.

/etc/shadow
    Informations sécurisées sur les comptes utilisateurs.

/etc/group
    Informations sur les groupes.

/etc/gshadow
    Informations sécurisées sur les groupes.

/etc/default/useradd
    Valeurs par défaut pour la création de comptes.

/etc/shadow-maint/useradd-pre.d/*, /etc/shadow-maint/useradd-post.d/*
    Run-part files to execute during user addition. The environment variable ACTION will be populated with useradd and SUBJECT with the username. useradd-pre.d will be executed prior to any user addition. useradd-post.d will execute after user addition. If a script exits non-zero then execution will terminate.

/etc/skel/
    Répertoire contenant les fichiers par défaut.

/etc/subgid
    IDs des groupes subalternes d'un utilisateur.

/etc/subuid
    IDs de utilisateurs subalternes d'un utilisateur.

/etc/login.defs
    Configuration de la suite des mots de passe cachés « shadow password ».

VALEURS DE RETOUR

The useradd command exits with the following values:

0
    success

1
    can't update password file

2
    invalid command syntax

3
    invalid argument to option

4
    UID already in use (and no -o)

6
    specified group doesn't exist

9
    username already in use

10
    can't update group file

12
    can't create home directory

14
    can't update SELinux user mapping

VOIR AUSSI

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