package Redirect_Hash;
sub TIEHASH {
  my ($class, $prefix) = @_;
  $prefix = 'redirect_' unless defined $prefix;
  my $self = [$prefix, {}];
  bless $self => $class;
}

sub STORE {
  my ($self, $key, $value) = @_;
  my ($prefix, $hash) = @$self;
  if (index($key, $prefix) == 0) {
    my $truncated = substr($key, length($prefix));
    $hash->{$truncated} = $value
      unless exists $hash->{$truncated};
  } 
  $hash->{$key} = $value;
}

sub FETCH {
  my ($self, $key) = @_;
  my ($prefix, $hash) = @$self;
  $hash->{$key};
}

##</code><code>##

tie %h => Redirect_Hash;

$h{redirect_name} = 'boondoggle';
print $h{name}, "\n"; # prints 'boondoggle'

$h{name} = 'Fred';
print $h{name}, "\n"; # still prints 'Fred'
print $h{redirect_name}, "\n"; # still prints 'boondoggle'