Tk::exit - End the application
use Tk qw(exit);
Terminate the process, returning returnCode
to the system as the exit
status. If returnCode
isn't specified then it defaults to 0.
If calling "exit" from code invoked via a Tk callback then this Tk
version of "exit" cleans up more reliably than using the perl
Using "exit" from a forked process will terminate both the child
the parent process. As "Tk::exit" is imported by
default one should use "CORE::exit" in the forked process instead.