Problem
1. Enter a : and press [Enter]. Next run type :. What do you conclude?
2. UNIX commands must be in lowercase and must not have extensions. True or false?
3. Name three UNIX commands whose names are more than five characters long.
4. Find out whether these commands are internal or external: echo, date, pwd, and ls.
5. If two commands with the same filename exist in two directories in PATH, how can they be executed?