The program doesn't seem to work on Windows, and I don't have the time
right now to debug it. So, at the moment, the program isn't supported on Windows.
Instead of printing out the contents early on (which wouldn't allow it to work
with '-n'), I skip the loop that applies colors based on the regular expressions.
I added a 'line number' flag ('-n') which will print the line number
with padding before every line. To ensure that a line number isn't printed when
trying to 'ccat' an empty file, I added a check to see if the file is empty.
If it is, the program exits.