useradd [options] LOGIN
useradd -D [options]
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).
The options which apply to the useradd command are:
-b, --base-dir BASE_DIR
The default base directory for the system if -dHOME_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
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
Any text string. It is generally a short description of the login,
and is currently used as the field for the user's full name.
-d, --home 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
See below, the subsection "Changing the default values".
-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
The group name or number of the user's initial login group. The
group name must exist. A group number must refer to an already
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.
Display help message and exit.
-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
If this option is not set, the skeleton directory is defined by the
SKEL variable in /etc/default/useradd or, by default, /etc/skel.
If possible, the ACLs and extended attributes are copied.
-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 ageing, even though system account has
no password at all. Multiple -K options can be specified, e.g.: -K
Do not add the user to the lastlog and faillog databases.
By default, the user's entries in the lastlog and faillog databases
are resetted to avoid reusing the entry from a previously deleted
For the compatibility with previous Debian's useradd, the -O option
is also supported.
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
Allow the creation of a user account with a duplicate (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.
You should make sure the password respects the system's password
Create a system account.
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
Note that useradd will not create a home directory for such an
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.
-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
-Z, --selinux-user SEUSER
The SELinux user for the user's login. The default is to leave this
field blank, which causes the system to select the default SELinux
Changing the default values
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
This option sets the HOME variable in /etc/default/useradd.
-e, --expiredate EXPIRE_DATE
The date on which the user account is disabled.
This option sets the EXPIRE variable in /etc/default/useradd.
-f, --inactive INACTIVE
The number of days after a password has expired before the account
will be disabled.
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
The name of a new user's login shell.
This option sets the SHELL variable in /etc/default/useradd.
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).
You may not add a user to a NIS or LDAP group. This must be performed
on the corresponding server.
Similarly, if the username already exists in an external user database
such as NIS or LDAP, useradd will deny the user account creation
Usernames may only be up to 32 characters long.
The following configuration variables in /etc/login.defs change the
behavior of this tool:
Indicate if a home directory should be created by default for new
This setting does not apply to system users, and can be overridden
on the command line.
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.
The mail spool directory. This is needed to manipulate the mailbox
when its corresponding user account is modified or deleted. If not
specified, a compile-time default is used.
Defines the location of the users mail spool files relatively to
their home directory.
The MAIL_DIR and MAIL_FILE variables are used by useradd, usermod, and
userdel to create, move, or delete the user's mail spool.
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.
The maximum number of days a password may be used. If the password
is older than this, a password change will be forced. If not
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
SYS_UID_MAX (number), SYS_UID_MIN (number)
Range of user IDs used for the creation of system users by useradd
The default value for SYS_UID_MIN (resp. SYS_UID_MAX) is 101
UID_MAX (number), UID_MIN (number)
Range of user IDs used for the creation of regular users by useradd
The default value for UID_MIN (resp. UID_MAX) is 1000 (resp.
The file mode creation mask is initialized to this value. If not
specified, the mask will be initialized to 022.
useradd and newusers use this mask to set the mode of the home
directory they create
It is also used by pam_umask as the default umask value.
If set to yes, userdel will remove the user's group if it contains
no more members, and useradd will create by default a group with
the name of the user.
User account information.
Secure user account information.
Group account information.
Secure group account information.
Default values for account creation.
Directory containing default files.
invalid command syntax
invalid argument to option
UID already in use (and no -o)
specified group doesn't exist
username already in use
can't update group file
can't create home directory
can't update SELinux user mapping
chfn(1), chsh(1), passwd(1), crypt(3), groupadd(8), groupdel(8),
groupmod(8), login.defs(5), newusers(8), userdel(8), usermod(8).
shadow-utils 220.127.116.11 05/16/2017 USERADD(8)
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