Thread: Breaking out of a loop with esc key

I am writing a datalogger program that uses an infinite loop to log data from the parallel port to a file. I can use Ctrl-C to exit the program but the file handle is not released. Is there a way to use the Esc-key or an F-key to break the loop to close files and end the program systematically?

I'm a novice. Can you give me an example. My compiler has the signal.h header file. I will be compiling to run this program on a DOS machine.