F:\>perl -v

This is perl, v5.6.0 built for MSWin32-x86-multi-thread
(with 1 registered patch, see perl -V for more detail)

Copyright 1987-2000, Larry Wall

Binary build 623 provided by ActiveState Tool Corp.
...et c...
F:\>perl -de 0
Default die handler restored.

Loading DB routines from perl5db.pl version 1.07
Editor support available.

Enter h or `h h' for help, or `perldoc perldebug' for more help.

main::(-e:1):   0
  DB<1> use strict;

  DB<2> use warnings;

  DB<3> print undef;

  DB<4> print $x[undef];

  DB<5> q

##</code><code>##

perl -wde 0