man PadWalker () - play with other peoples' lexical variables

NAME

PadWalker - play with other peoples' lexical variables

SYNOPSIS

  use PadWalker qw(peek_my peek_sub);
  ...

DESCRIPTION

PadWalker is a module which allows you to inspect (and even change!) lexical variables in any subroutine which called you. It will only show those variables which are in scope at the point of the call.

The CWpeek_my routine takes one parameter, the number of call levels to go back. (It works the same way as caller() does.) It returns a reference to a hash which associates each variable name with a reference to its value. The variable names include the prefix, so CW$x is actually '$x'.

For example: 

  my $x = 12;
  my $h = peek_my (0);
  ${$h->{'$x'}}++;


  print $x;  # prints 13

Or a more complex example: 

  sub increment_my_x {
    my $h = peek_my (1);
    ${$h->{'$x'}}++;
  }


  my $x=5;
  increment_my_x;
  print $x;  # prints 6

The CWpeek_sub routine takes a coderef as its argument, and returns a hash of the lexical variables used in that sub.

AUTHOR

Robin Houston <robin@cpan.org>

With contributions from Richard Soberberg, and bug-spotting from Peter Scott.

SEE ALSO

Devel::LexAlias, Devel::Caller, Sub::Parameters

COPYRIGHT

Copyright (c) 2000-2002, Robin Houston. All Rights Reserved. This module is free software. It may be used, redistributed and/or modified under the same terms as Perl itself.