Most people don't realize that a localized copy of a variable does not retain its original value. Unless you initialize the variable when you local-ize it, it defaults to undef. If you want the variable to retain its original value, just initialize it to itself. If you really do want the localized copy to be undef, then make it explicit.

  package Foo;
  $Bar = '42';
  package Baz;
  sub frobulate {
      local $Foo::Bar;              #not ok, local $Foo::Bar is 'undef'
      local $Foo::Bar = undef;      #ok, local $Foo::Bar is obviously 'undef'
      local $Foo::Bar = $Foo::Bar;  #ok, local $Foo::Bar still equals '42'


Jeffrey Ryan Thalhammer <thaljef@cpan.org>


Copyright (c) 2005-2007 Jeffrey Ryan Thalhammer. All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself. The full text of this license can be found in the LICENSE file included with this module.