Implement a simple Linux shell in C capable of executing a sequence of programs that communicate through a pipe. For example, if the user types ls | wc, your program should fork off the two programs, which together will calculate the number of files in the directory. For this, you will need to use several of the Linux system calls described in this chapter: fork, exec, open, close, pipe, dup2, and wait. Note: You will to replace stdin and stdout in the child process with the pipe file descriptors; that is the role of dup2.