Definition: integer i = check_break()
Description: Return the number of times that control-c or control-Break have been pressed since the last call to check_break(), or since the beginning of the program if this is the first call.
Comments: This is useful after you have called allow_break(0) which prevents control-c or control-Break from terminating your program. You can use check_break() to find out if the user has pressed one of these keys. You might then perform some action such as a graceful shutdown of your program.

Neither control-c nor control-Break will be returned as input characters when you read the keyboard. You can only detect them by calling check_break().
k = get_key()
if check_break() then
    puts(1, "Shutting down...")
end if
See Also: allow_break, get_key