Difference between revisions of "Useradd"

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[[Category:Linux Shell Commands]]
{{to htyp}}
[[Techniques]]: [[Linux]]: [[{{PAGENAME}}]]
==Manpage==
===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 [-k ''skeleton_dir''] | -M] [-n] [-o] [-p ''passwd''] [-r] [-l]
              [-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. The version provided with Red Hat Linux will create a group for each user added  to  the  system, unless the -n option is given.
===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 || The user's home directory will not be created, even if the  system wide settings from /etc/login.defs is to create home dirs.
|-
| -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.
|-
| -n || A group having the same name as the user being added to the system  will  be created by default. This option will turn off this Red Hat Linux specific behavior.
|-
| -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.
|-
| -r || This  flag  is  used to create a system account. That is, a user with  a  UID  lower  than  the  value  of  UID_MIN  defined  in /etc/login.defs  and  whose  password does not expire. Note that useradd will not create a  home  directory  for  such  an  user, regardless  of the default setting in /etc/login.defs.  You have to specify -m option if you want a home directory for  a  system account to be created.  This is an option added by Red Hat.
|-
| -l || Do  not  add  the  user  to  the last login log file. This is an option added by Red Hat.
|-
| -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  userâs  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 userâs 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.
 
This  version  of  useradd  was  modified  by  Red  Hat to suit Red Hat user/group conventions.
 
===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/gshadow || - secure group information
|-
| /etc/default/useradd || - default information
|-
| /etc/login.defs || - system-wide settings
|-
| /etc/skel/ || - directory containing default files
|}
===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 doesnât 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)
==Edit Log==
* '''2005-09-14''': Copied from Red Hat Fedora Core 4 manpage. Need to compare to some non-RedHat distro to see which bits are RedHat-only and mark them as such.

Latest revision as of 20:49, 14 October 2005

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