NAME

useradd − administer a new user login on the system

SYNOPSIS

useradd [−u uid [−o]] [−g group] [−G group[,group...] [−d dir] [−s shell]
   [−c comment] [−m [−k skel_dir]] [−f inactive] [−e expire] login
 useradd −D [−g group] [−b base_dir] [−f inactive] [−e expire]

DESCRIPTION

Invoking useradd without the −D option adds a new user entry to the /etc/passwd and /etc/shadow files.  It also creates supplementary group memberships for the user (-G option) and creates the home directory (-m option) for the user if requested.  The new login remains locked until the passwd(1M) command is executed. 

Invoking useradd −D with no additional options displays the default values for group, base_dir, shel_dir, shell, inactive, and expire.  The values for group, base_dir, inactive, expire, and shell are used for invocations without the −D option. 

Invoking useradd −D with −g, −b, −f, or −e (or any combination of these) sets the default values for the respective fields.  (As installed, the default group is other (group ID of 1) and the default value of base_dir is /home).  Subsequent invocations of useradd without the −D option use these arguments. 

The system file entries created with this command have a limit of 512 characters per line.  Specifying long arguments to several options may exceed this limit. 

The following options are available:

−u uid The UID of the new user.  This UID must be a non-negative decimal integer below MAXUID as defined in param.h.  The UID defaults to the next available (unique) number above the highest number currently assigned.  For example, if UIDs 100, 105, and 200 are assigned, the next default UID number will be 201.  (UIDs from 0-99 are reserved.) 

−o This option allows a UID to be duplicated (non-unique). 

−g group
An existing group’s integer ID or character-string name. Without the −D option, it defines the new user’s primary group membership and defaults to the default group.  You can reset this default value by invoking useradd −D −g group. 

−G group
An existing group’s integer ID or character-string name. It defines the new user’s supplementary group membership. Duplicates between group with the −g and −G options are ignored.  No more than NGROUPS_MAX groups may be specified. 

−d dir The home directory of the new user.  It defaults to base_dir/login, where base_dir is the base directory for new login home directories and login is the new login. 

−s shell
Full pathname of the program used as the user’s shell on login. It defaults to an empty field causing the system to use /sbin/sh as the default.  The value of shell must be a valid executable file. 

−c 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. This information is stored in the user’s /etc/passwd entry. 

−m Create the new user’s home directory if it doesn’t already exist.  If the directory already exists, it must have read, write, and execute permissions by group, where group is the user’s primary group. 

−k skel_dir
A directory that contains skeleton information (such as .profile) that can be copied into a new user’s home directory.  This directory must exist.  The system provides a “skel” directory (/etc/skel) that can be used for this purpose. 

−e expire
The date on which a login can no longer be used; after this date, no user will be able to access this login. (This option is useful for creating temporary logins.) You may type the value of the argument expire (which is a date) in any format you like (except a Julian date).  For example, you may enter 10/6/90 or October 6, 1990.  A value of “” defeats the status of the expired date. 

−f inactive
The maximum number of days allowed between uses of a login ID before that login ID is declared valid. Normal values are positive integers. A value of −1 defeats the status. 

login A string of printable characters that specifies the existing login name of the user.  It must exist and may not contain a colon (:) or a newline (\n). 

login A string of printable characters that specifies the new login name of the user.  It may not contain a colon (:) or a newline (\n). 

−b base_dir
The default base directory for the system. If −d dir is not specified.  base_dir is concatenated with the user’s login to define the home directory.  If the -m option is not used, base_dir must exist. 

FILES

/etc/passwd
/etc/shadow
/etc/group
/etc/skel

SEE ALSO

groupadd(1M), groupdel(1M), groupmod(1M), logins(1M), passwd(1), passwd(1M), userdel(1M), usermod(1M), users(1)

DIAGNOSTICS

The useradd command exits with one of the following values:

0 The command was executed successfully. 

2 The command line syntax was invalid.  A usage message for the useradd command is displayed. 

3 An invalid argument was provided with an option. 

4 The uid specified with the −u option is already in use. 

5 The password files are inconsistent. 

6 The group specified with the −g option does not exist. 

9 The specified login is not unique. 

10 Cannot update /etc/group.  The login was added to the /etc/passwd file but not to the /etc/group file. 

12 Unable to create the home directory (with the −m option) or unable to complete the copy of skel_dir to the home directory.