=head1 The Perl Debugger
+"As soon as we started programming, we found to our
+surprise that it wasn't as easy to get programs right
+as we had thought. Debugging had to be discovered.
+I can remember the exact instant when I realized that
+a large part of my life from then on was going to be
+spent in finding mistakes in my own programs."
+--Maurice Wilkes, 1949
+
If you invoke Perl with the B<-d> switch, your script runs under the
Perl source debugger. This works like an interactive Perl
environment, prompting for debugger commands that let you examine