How find the current system runlevel?

What is the expected output of the following command: unset x; test -z $x && echo 1

What does the Linux 'yes' command do?

You need which of the following access modes in order to cd to a system directory?

The ________ command can be used to 'kill' the 'X server'.

What is the purpose of the 'tset' command?

A ____ is commonly packaged with a new computer system.

What command can be used to forward the port 8000 on the local machine to the port 80 on a remote machine with IP 192.168.0.10?

Which of the following commands can you use to transfer files securely to and from remote systems?

Which of the following files is executed by bash when it is launched as a non-login shell?

What is Postfix?