1. Objectives

i) To use system calls: fork, wait, execvp, open, close, dup, dup2, and pipe in program

ii) To write a shell (a command line interpreter)

2. Your own shell should support the following features:

1) Your program will keep accepting new commands lines until users input exit. Your shell should have a prompt string.

2) A users command line may or may not have < at the beginning.

3) A users command line may or may not have > in the end.

4) There may be up to 9 pipes in a command line (its OK if you want to support more than 9 pipes).

5) A user may run a command line as a background process (i.e., the command line ends with &).

Note: All System Calls must have error checking!