You would be well advised to spend some time looking around the Tutorials section here. The answer to Question A can be found in Including files.

Question B doesn't have such a straight forward answer and depends somewhat on the OS you are using. However you really need to think about what you want to achieve by interrupting processing in a "nice" fashion. Perl allows you to trap Ctrl+C and handle it in a tidy fashion by assigning a sigint handler using $SIG{INT} = \&sigint_handler where sigint_handler is your handler routine.