useradd
Name
useradd -- create a new user or update default new user information
Synopsis
useradd [-c comment] [-d home_dir] [-g initial_group] [-G group...] [-m [-k skeleton_dir]] [-p passwd] [-r] [-s shell] [-u uid [-o]] login
useradd -D [-g default_group] [-b default_home] [-s default_shell]Description
When invoked without the -D
option, and with appropriate privilege,
useradd creates a new
user account using the values specified on the command line and the
default values from the system. The new user account will be entered
into the system files as needed, the home directory will be created,
and initial files copied, depending on the command line options.
When invoked with the -D
option, useradd will either
display the current default values, or,
with appropriate privilege, update the default values from
the command line. If no options are specified, useradd
displays the current default values.
The useradd command is a system administration utility,
see Path For System Administration Utilities.
Standard Options
-c comment | | specifies the new user's password file comment field value. |
-d home_dir | | creates the new user using home_dir as the value for the
user's login directory. The default is to append the login name to
default_home and use that as the login directory name. |
-g initial_group | | specifies the group name or number of the user's initial login group.
The group name shall exist. A group number shall refer to an already
existing group. If -g
is not specified, the implementation will follow
the normal user
default for that system. This may create a new group or choose a default
group that normal users are placed in. Applications which require control
of the groups into which a user is placed should specify
-g. |
-G group[,...] | | specifies 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. |
-m [-k skeleton_dir] | | specifies the user's home directory will be created if it does not exist.
The files contained in skeleton_dir
will be copied to the home directory
if the -k
option is used, otherwise the files contained in
/etc/skel
will be used instead. Any directories contained in
skeleton_dir or
/etc/skel
will be created in the user's home directory as well. The
-k
option is only valid in conjunction with the
-m option. The
default is to not create the directory and to not copy any files. |
-p passwd | | is the encrypted password, as returned by crypt().
The default is to
disable the account. |
-r | | creates a system account, that is, a user with a
User ID in the range reserved for system account users. If there is not a
User ID free in the reserved range the command will fail. |
-s shell | | specifies 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. |
-u uid [-o] | | specifies the numerical value of the user's ID. This value shall be unique,
unless the -o option is used. The value shall be non-negative.
The default is the smallest ID value greater than 499 which is not yet used. |
Change Default Options
-b default_home | | specifies the initial path prefix for a new user's home directory. The user's
name will be affixed to the end of default_home to create the new
directory name if the -d option is not used when creating a new
account. |
-g default_group | | specifies the group name or ID for a new user's initial group. The named
group shall exist, and a numerical group ID shall have an existing entry. |
-s default_shell | | specifies the name of the new user's login shell. The named program will be
used for all future new user accounts. |
-c comment | | specifies the new user's password file comment field value. |
Application Usage
The -D
option will typically be used by system administration
packages. Most applications should not change defaults which will
affect other applications and users.