Problem
1. Run the following commands, and then invoke ls. What do you conclude?
echo > README [Enter]
echo > readme [Enter]
2. Enter the following commands, and note your observations:
(i) who and tty,
(ii) tput clear,
(iii) id,
(iv) ps and echo $.
3. When you log in, a program starts executing at your terminal. What is this program known as? Name four types of this program that are available on a system.