useradd 8 useradd Create a new user or update default new user information useradd -c comment -d home_dir -e expire_date -f inactive_days -g initial_group -G group1 ,group2, , groupN -M -m -k skeleton_dir -o -p passwd -s shell -u uid login useradd -D -g group -b home_dir -e expire_date -f inactive_days -s shell 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 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 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 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. -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 crypt3 . 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. 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 home_dir The initial path prefix for a new user's home directory. The user's name will be affixed to the end of home to create the new directory name if the -d option is not used when creating a new account. -e expire_date The date on which the user account is disabled. -f inactive The number of days after a password has expired before the account will be disabled. -g 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 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. The system administrator is responsible for placing the default user files in the /etc/skel/ directory. You may not add a user to an NIS group. This must be performed on the NIS server. /etc/passwd user account information /etc/shadow secure user account information /etc/group group account information /etc/default/useradd default information /etc/skel/ directory containing default files 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 chfn1 , chsh1 , passwd1 , crypt3 , groupadd8 , groupdel8 , groupmod8 , userdel8 , usermod8 Julianne Frances Haugh (jockgrrl@ix.netcom.com)