This program is to give you practice in the use of UNIX functions fork() and pipe() and to implement message communication between processes. In this program you will implement a simple UNIX shell in C. The shell reads a command line from the input, and it forks a process to execute that command. UNIX fork() command automatically duplicates all open file descr iptors in the child. As a result, the input and output devices for the child are the same as that of the parent. The parent will wait for the child to finish before it reads the next command. Recall in UNIX programs the read and write commands are the same whether your input/output device is a keyboard/screen or files or pipes. With appropriate file descr iptors you can designate any device for input input/output.