USERADD
Section: Maintenance Commands (8)
Index
Return to Main Contents
NAME
useradd - Create a new user or update default new user information
SYNOPSIS
- useradd [-c comment] [-d home_dir]
-
[-e expire_date] [-f inactive_days]
[-g initial_group] [-G group[,...]]
[[-M] -m [-k skeleton_dir]] [-o] [-p passwd]
[-s shell] [-u uid] login
- useradd -D [-g default_group] [-b default_home]
-
[-e default_expire_date] [-f default_inactive]
[-s default_shell]
DESCRIPTION
Creating New Users
When invoked without the -D option, the useradd command creates
a new user account using the values specified on the command line and 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.
OPTIONS
The options which apply to the
useradd command are:
- -c comment
-
The new user's password file comment field.
- -d 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
default_home and use that as the login directory name.
- -e expire_date
-
The date on which the user account will be disabled. The date is specified
in the format YYYY-MM-DD.
- -f inactive_days
-
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. The default value is -1.
- -g initial_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. The
default group number is 1 or whatever is specified in
/etc/default/useradd.
- -G group,[...]
-
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
-
RedHat added the CREATE_HOME option in login.defs in their version of
shadow-utils (which makes -m the default, with new -M option to turn it
off). Unfortunately, this changes the way useradd works (it can be run by
scripts expecting some standard behaviour), compared to other Unices and
other Linux distributions, and also adds a lot of confusion.
- -m
-
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.
- -o
-
Allow create user with duplicate (non-unique) UID.
- -p passwd
-
The encrypted password, as returned by crypt(3). The default is to
disable the account.
- -s 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.
- -u 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 999 and greater than every other user.
Values between 0 and 999 are typically reserved for system accounts.
Changing the default values
When invoked with the -D option, useradd will either display the
current default values, or update the default values from the command line.
The valid options are
- -b default_home
-
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.
- -e default_expire_date
-
The date on which the user account is disabled.
- -f default_inactive
-
The number of days after a password has expired before the account will be
disabled.
- -g default_group
-
The group name or ID for a new user's initial group. The named group must
exist, and a numerical group ID must have an existing entry .
- -s default_shell
-
The name of the new user's login shell. The named program will be used for
all future new user accounts.
If no options are specified, useradd displays the current default
values.
NOTES
The system administrator is responsible for placing the default user files
in the /etc/skel/ directory.
CAVEATS
You may not add a user to an NIS group. This must be performed on the NIS
server.
FILES
/etc/passwd - user account information
/etc/shadow - secure user account information
/etc/group - group information
/etc/default/useradd - default information
/etc/skel/ - directory containing default files
EXIT VALUES
- The useadd 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
13 - can't create mail spool
SEE ALSO
chfn(1),
chsh(1),
passwd(1),
crypt(3),
groupadd(8),
groupdel(8),
groupmod(8),
userdel(8),
usermod(8)
AUTHOR
Julianne Frances Haugh (jockgrrl@ix.netcom.com)
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- Creating New Users
-
- OPTIONS
-
- Changing the default values
-
- NOTES
-
- CAVEATS
-
- FILES
-
- EXIT VALUES
-
- SEE ALSO
-
- AUTHOR
-
This document was created by
man2html,
using the manual pages.
Time: 00:17:10 GMT, May 13, 2005
www.fiveanddime.net