System administration command. Create new user accounts or update default account information. Unless invoked with the -D option, user must be given. useradd will create new entries in system files. Home directories and initial files may also be created as needed.
Home directory. The default is to use user as the directory name under the home directory specified with the -D option.
Account expiration date. date is in the format MM/DD/YYYY. Two-digit year fields are also accepted. The value is stored as the number of days since January 1, 1970. This option requires the use of shadow passwords.
Permanently disable account this many days after the password has expired. A value of -1 disables this feature. This option requires the use of shadow passwords.
Initial group name or ID number. If a different default group has not been specified using the -D option, the default group is 1.
Supplementary groups given by name or number in a comma-separated list with no whitespace.
Copy default files to the user’s home directory. Meaningful only when used with the -m option. Default files are copied from /etc/skel/ unless an alternate dir is specified.
Make user’s home directory if it does not exist. The default is not to make the home directory.
Do not create a home directory for the user, even if the system default in /etc/login.defs is to create one.