As with groups, Ubuntu provides several command-line tools for managing users, but also provides graphical tools for doing so. Most experienced system administrators prefer the command-line tools because they are quick and easy to use, are always available even when there is no GUI, and because they can be included in scripts she may write if the system administrator wants to write a quick program to perform a repetitive task. Here are the most common commands to manage users:
useradd—This command adds a new user account to the system. Its options permit the system administrator to specify the user’s
/home directory and initial group or to create the user with the default
/home directory and group assignments (based on ...