Type this in python

In this assignment you will implement the RUN functionality of your command interpreter.

Your RUN command takes one argument. The executable file specified by the argument should be run and when finished, the prompt displayed. The syntax is:

RUN executable-file

The algorithm for RUN would be as follows.

Define a parent function in which you:

Fork a child process.

Block the parent process to wait till child process ends

If child process is created successfully, call a child function that implements the child process

Define a child function from which you execute the executable program

This will require the following library functions (in Python on UNIX)

os.fork( ) creates a child process and returns the PID of the child process to the parent. Child PID is 0.

subprocess.call(path/executableProgram) executes a program in the current process

os.waitpid(pid,0) causes the parent to block until the child finishes