Coding Challenge

Here is a little coding challenge. Learning how to solve this probably won't make you a better programmer (it may make you worse) but it's fun anyway. You are given a file named "helloworld.cxx" that contains the following code.

#include <stdio.h>
#include "muck.h"

int 
main(int argc, char **argv)
{
    printf("%s\n", "Hello World!");
}

You can't edit this file! Your job is to write the "muck.h" header file. When you're done compile "helloworld.cxx" and run it and the output should be "Goodbye!" followed by a newline. Nothing more nothing less. Remember you can only modify "muck.h" and you must compile "helloworld.cxx" unmodified. My solution and it's Makefile.