The subject of this programming assignment is using Linux/Unix system calls dealing

with exec and signals.-The application will be a simple “memo” program that accepts lines

of text from the terminal, but then processes them slightly before writing the lines to a file.

To implement this application, you are to write two C programs. The first one will be the

parent program, and will do the following: (1) run the other program in a subprocess　(2)

iteratively prompt the user to enter a line of text　(3) write each entered line of text to

a temporary file and signal the child. The second program will run as the child, and will

do the following: (1) when signaled by the parent, it will obtain the entered line from the

temporary file　(2) it will process/expand each line (as described below) and write the result

out to the output file.