package BaseClass;

sub _classobj {
   my $invocant = shift;
   my $class = ref $invocant || $invocant;
   no strict "refs";
   return \%$class;
}

sub new {
   my $invocant = shift;
   my $class = ref $invocant || $invocant;
   my $classData = $class->_classobj();
   my $name = $classData->{Column_Header}; 
   my $value = (@_)
                  ? shift
                  : undef;

   bless { name   => "$name",
           value  => "$value",
           cdata  => \%classData,
         }, $class;
}

sub get_column { 
   my $invocant = shift;
   my $class = ref ($invocant) || $invocant;
   my $cdata = $class->_classobj;

   unless defined "$cdata" {
      print "class data not found \n";
      die;
   }
   my $column = $$cdata->{Input_column};
   return $column;
}
1;

##</code><code>##

package ChildClass;
use base qw(BaseClass);

our %ChildClass = (
   Blank_ok     => 'no',            
   Column_header=> '^(cell|name)$', 
   Field_length => 20,
   Input_column => 'Unknown',       
   Invalid_characters => '[^\W-]',  
);
1;

##</code><code>##

#! /usr/bin/perl

use strict;
use warnings;
use diagnostics;
use Carp;

use ChildClass;          
print "column: ", ChildClass->get_column;

##</code><code>##

> p $class<br>
ChildClass<br>
> x %ChildClass<br>
empty array<br>
> x %ChildClass::ChildClass<br>
0  'Invalid_characters'<br>
1  '[^\\W-]'<br>
2  'Column_header'<br>
3  '^(cell|name)$'<br>
4  'Blank_ok'<br>
5  'no'<br>
6  'Input_column'<br>
7  'Unknown'<br>
8  'Field_length'<br>
9  20