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NAME

useradd - erstellt einen neuen Benutzer oder aktualisiert die Standardwerte für neue Benutzer

ÜBERSICHT

useradd [Optionen] ANMELDENAME

useradd -D

useradd -D [Optionen]

BESCHREIBUNG

useradd is a low level utility for adding users. On Debian, administrators should usually use adduser(8) instead.

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).

OPTIONEN

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

Eine beliebige Zeichenkette. Dies ist für gewöhnlich eine kurze Beschreibung des Logins und wird im Moment im Feld für den vollständigen Namen des Benutzers gespeichert.

-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. The directory HOME_DIR does not have to exist but will not be created if it is missing.

-D, --defaults

Lesen Sie dazu unten den Abschnitt »Die Standardwerte verändern«.

-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

Die Anzahl von Tagen nach Ablaufen des Passworts bis das Konto dauerhaft deaktiviert wird. Ein Wert von 0 deaktiviert das Konto, sobald das Passwort abläuft. Ein Wert von -1 schaltet diese Funktion ab.

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

Der Name oder die Nummer der anfänglichen Anmeldegruppe des Benutzers. Der Gruppenname muss existieren. Die Gruppenzahl muss auf eine bereits vorhandene Gruppe verweisen.

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

zeigt die Hilfe an und beendet das Programm

-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.

Soweit möglich, werden die ACLs und erweiterten Attribute kopiert.

-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

Fügt den Benutzer nicht zu den Datenbanken lastlog und faillog hinzu.

By default, the user's entries in the lastlog and faillog databases are reset to avoid reusing the entry from a previously deleted user.

For the compatibility with previous Debian's useradd, the -O option is also supported.

-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.

-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

Erlaubt das Erstellen eines Benutzerkontos mit einer schon vergebenen (nicht eindeutigen) UID.

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.

Sie sollten sicherstellen, dass das Passwort den Passwortrichtlinien des Systems entspricht.

-r, --system

erstellt ein Systemkonto

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

erstellt eine Gruppe mit dem gleichen Name wie der Benutzer und fügt diesen der Gruppe hinzu

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

Der SELinux-Benutzer für den Benutzer nach seiner Anmeldung. Standardmäßig bleibt dieses Feld leer und es wird dem System überlassen, den SELinux-Benutzer zu bestimmen.

Die Standardwerte verändern
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

das Datum, an dem das Benutzerkonto abgeschaltet wird

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

-f, --inactive INACTIVE

die Anzahl von Tagen nach dem Ablaufen des Passworts bis das Konto deaktiviert wird

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

der Name der Anmelde-Shell des neuen Benutzers

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

ANMERKUNGEN

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).

WARNUNGEN

Sie dürfen einen Benutzer nicht einer NIS- oder LDAP-Gruppe hinzufügen. Dies muss auf dem entsprechenden Server durchgeführt werden.

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

It is usually recommended to only use usernames 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 usernames must neither start with a dash ('-') nor plus ('+') nor tilde ('~') nor contain a colon (':'), a comma (','), or a whitespace (space: ' ', end of line: '\n', tabulation: '\t', etc.). Note that using a slash ('/') may break the default algorithm for the definition of the user's home directory.

Benutzernamen dürfen nur bis zu 32 Zeichen lang sein.

KONFIGURATION

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

DATEIEN

/etc/passwd

Informationen zu den Benutzerkonten

/etc/shadow

verschlüsselte Informationen zu den Benutzerkonten

/etc/group

Informationen zu den Gruppenkonten

/etc/gshadow

sichere Informationen zu den Gruppenkonten

/etc/default/useradd

Standardwerte für die Erstellung eines Kontos

/etc/skel/

Verzeichnis, das die Standarddateien enthält

/etc/subgid

Per user subordinate group IDs.

/etc/subuid

Per user subordinate user IDs.

/etc/login.defs

Konfiguration der Shadow-Passwort-Werkzeugsammlung

RÜCKGABEWERTE

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

SIEHE AUCH

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).

COMMENTS