Set an expiration date for the user account, format YYYY-MM-DD
-m, --create-home
Create the user’s home directory if it does not exist. The files and directories contained in the skeleton directory (which can be defined with the -k option) will be copied to the home directory.
By default, if this option is not specified and CREATE_HOME is not enabled, no home directories are created.
-s, --shell SHELL
login shell of the new account
-u, --uid UID
user ID of the new account
Changing the default values
When invoked with only the -D option, useradd will display the current default values.
When invoked with -D plus other options, useradd will update the default values for the specified options. Valid default-changing options are: