Here are the guts of a module that I'm working on called Globwalker.pm. It's supposed to give you a list of objects of a given type in a given typeglob (e.g. for example all subs in main::). It seem to work OK for most glob types, but I'm getting strange results for scalars. I assume this is because the scalar knob is defined as soon as the typeglob comes into existance.

Does anyone have any idea how I can work out if the scalar has really been used?

package Globwalker;

use strict;
use vars qw($VERSION @ISA @EXPORT @EXPORT_OK);

require Exporter;

@ISA = qw(Exporter);
@EXPORT_OK = qw(get_things get_subs get_scalars get_arrays 
                get_hashes get_filehandles);
$VERSION = '0.01';

sub get_things {
  my $thing = shift;
  my $pkg = shift || caller;
  my @things;

  no strict 'refs'; # WARNING: Deep magic here!
  while (my ($sym_name, $sym_glob) = each %{"${pkg}::"}) {
    push @things, $sym_name if defined *$sym_glob{$thing};
  }

  @things;
}

sub get_subs { get_things('CODE', shift || caller) };
sub get_scalars { get_things('SCALAR', shift || caller) };
sub get_arrays { get_things('ARRAY', shift || caller) };
sub get_hashes { get_things('HASH', shift || caller) };
sub get_filehandles { get_things('IO', shift || caller) };

1;

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<http://www.dave.org.uk>

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and the boring jobs bearable" - me

In reply to Finding out if a scalar exists in a typeglob by davorg

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