NAME
useradd - create a new user or update default new user information 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 USERGROUPSENAB). OPTIONS The options which apply to the useradd command are:
-b, base-dir BASEDIR
The default base directory for the system if -dHOMEDIR is not specified. BASEDIR is concatenated with the account name to define the home directory. The BASEDIR must exist otherwise the home directory cannot be created. 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-dir HOMEDIR The new user will be created using HOMEDIR as the value for the user's login directory. The default is to append the LOGIN name to BASEDIR and use that as the login directory name.
-D, defaults See below, the subsection "Changing the default values".
-e, expiredate EXPIREDATE 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 The number of days after a password expires until the account is permanently disabled. A value of 0 disables the account as soon as
the password has expired, and a value of -1 disables the feature. 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 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 existing group. If not specified, the behavior of useradd will depend on the USERGROUPSENAB 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 Display help message and exit.
-k, skel SKELDIR 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. If possible, the ACLs and extended attributes are copied.
-K, key KEY=VALUE Overrides /etc/login.defs defaults (UIDMIN, UIDMAX, UMASK, PASSMAXDAYS and others).
Example: -K PASSMAXDAYS=-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
UIDMIN=100-K UIDMAX=499
-l, no-log-init 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 user.
-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 CREATEHOME 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 not create the user's home directory, even if the system wide setting from /etc/login.defs (CREATEHOME) 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 USERGROUPSENAB variable in /etc/login.defs.
-o, non-unique
Allow the creation of a user account with a duplicate (non-unique) 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. You should make sure the password respects the system's password policy.
-r, system Create a system account. System users will be created with no aging information in /etc/shadow, and their numeric identifiers are chosen in the
SYSUIDMIN-SYSUIDMAX range, defined in /etc/login.defs, instead
of UIDMIN-UIDMAX (and their GID counterparts for the creation of groups). Note that useradd will not create a home directory for such an user, regardless of the default setting in /etc/login.defs
(CREATEHOME). You have to specify the -m options if you want a home directory for a system account to be created.
-R, root CHROOTDIR Apply changes in the CHROOTDIR directory and use the configuration files from the CHROOTDIR 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 UIDMIN and greater than every other user.
See also the -r option and the UIDMAX description.
-U, user-group Create a group with the same name as the user, and add the user to this group.
The default behavior (if the -g, -N, and -U options are not specified) is defined by the USERGROUPSENAB variable in /etc/login.defs.
-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 user. 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 BASEDIR The path prefix for a new user's home directory. The user's name will be affixed to the end of BASEDIR 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 EXPIREDATE 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 USERGROUPSENAB 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. 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). CAVEATS 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 request. Usernames may only be up to 32 characters long. CONFIGURATION The following configuration variables in /etc/login.defs change the behavior of this tool: CREATEHOME (boolean) Indicate if a home directory should be created by default for new users. This setting does not apply to system users, and can be overridden on the command line. GIDMAX (number), GIDMIN (number) Range of group IDs used for the creation of regular groups by useradd, groupadd, or newusers. The default value for GIDMIN (resp. GIDMAX) is 1000 (resp. 60000). MAILDIR (string) 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. MAILFILE (string) Defines the location of the users mail spool files relatively to their home directory. The MAILDIR and MAILFILE variables are used by useradd, usermod, and userdel to create, move, or delete the user's mail spool. If MAILCHECKENAB is set to yes, they are also used to define the MAIL environment variable. MAXMEMBERSPERGROUP (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. PASSMAXDAYS (number) 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
specified, -1 will be assumed (which disables the restriction). PASSMINDAYS (number) The minimum number of days allowed between password changes. Any password changes attempted sooner than this will be rejected. If
not specified, -1 will be assumed (which disables the restriction). PASSWARNAGE (number) The number of days warning given before a password expires. A zero means warning is given only upon the day of expiration, a negative value means no warning is given. If not specified, no warning will be provided. SYSGIDMAX (number), SYSGIDMIN (number) Range of group IDs used for the creation of system groups by useradd, groupadd, or newusers. The default value for SYSGIDMIN (resp. SYSGIDMAX) is 101
(resp. GIDMIN-1). SYSUIDMAX (number), SYSUIDMIN (number) Range of user IDs used for the creation of system users by useradd or newusers. The default value for SYSUIDMIN (resp. SYSUIDMAX) is 101
(resp. UIDMIN-1). UIDMAX (number), UIDMIN (number) Range of user IDs used for the creation of regular users by useradd or newusers. The default value for UIDMIN (resp. UIDMAX) is 1000 (resp. 60000). UMASK (number) 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 login to define users' initial umask. Note that this mask can be overridden by the user's GECOS line (if QUOTASENAB is set) or by the specification of a limit with the K identifier in limits(5). USERGROUPSENAB (boolean) Enable setting of the umask group bits to be the same as owner bits
(examples: 022 -> 002, 077 -> 007) for non-root users, if the uid is the same as gid, and username is the same as the primary group name. 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. FILES /etc/passwd User account information. /etc/shadow Secure user account information. /etc/group Group account information. /etc/gshadow Secure group account information. /etc/default/useradd Default values for account creation. /etc/skel/ Directory containing default files. /etc/login.defs Shadow password suite configuration. EXIT VALUES 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 SEE ALSO 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 4.1.5.1 10/30/2018 USERADD(8)