Linux Users, Groups and Processes

By the end of this lesson you can read the output of id, read one line of /etc/passwd, explain what sudo is for without using it, list running programs with ps, check a service with systemctl status, and explain the principle of least privilege. There is no lab in this lesson: every command is shown together with the exact result it prints, so you can read along and answer the questions. Numbers that change from machine to machine, such as process numbers and times, will look different on yours, and no question depends on them.