Problem
1. Write a script that makes rm behave interactively whenever it is used with more than three filenames.
2. A script named test containing the date and stty commands displays nothing when executed. Why does that happen? State two ways of making the script behave properly.
3. Write script logic that allows only romeo and henry to execute a program, and only from the terminals tty05 and tty06.
4. Name the external UNIX commands that were introduced in this chapter, and explain why they had to be discussed here.