package MyDBM;

require SDBM_File;
require Tie::Hash;
@ISA = qw(Tie::Hash);

sub TIEHASH {
    my $type = shift;
    my $ref = SDBM_File->new(@_);
    return bless {delegate => $ref}, $type;
}

sub AUTOLOAD {
    my $self = shift;

    # The Perl interpreter places the name of the
    # message in a variable called $AUTOLOAD.

    # DESTROY messages should never be propagated.
    return if $AUTOLOAD =~ /::DESTROY$/;

    # Remove the package name.
    $AUTOLOAD =~ s/^MyDBM:://;

    # Pass the message to the delegate.
    $self->{delegate}->$AUTOLOAD(@_);
}

package main;
use Fcntl qw( O_RDWR O_CREAT );

tie %number, "MyDBM", "oddnumbers", O_RDWR|O_CREAT, 0666;
$number{beast} = 666;