Useradd Command Defaults
Using useradd command is very is simple. Just give username as its argument and it will work and create user account for you.
will create a user account named alok on our Linux server.
The useradd command has very few options.
But, you should know that If an option is not specified, useradd will read its configuration file in /etc/default/useradd.
So by tweaking this file you can change the default behavior of useradd command.