my %newbase = ( %oldhash, %newhash );

##</code><code>##

sub prunecheck {   
    my ( $var1, $var2 ) = @_;
    my @var2keys = ();
    @var2keys = ( keys %$var2 ) if(ref($var2)=~ /HASH/);
    return unless defined $var1;

    for ( ref($var1) )
    {
        if (/HASH/)
        {
            if ( !(@var2keys) )
            {
                $$var1 = ();
            }
            else
            {

                for my $key1( keys %$var1 )
                {
                    if ( !exists( $$var2{$key1} ) )
                    {
                        delete( $$var1{$key1} );
                    }
                    else
                    {
                        # print "\t$key1\n";
                        prunecheck( $var1->{$key1}, $var2->{$key1} );
                    }
                }
            }
        }
        elsif (/ARRAY/)
        {
         foreach (@$var1)
         {
                prunecheck( $_, $var2 ) ;
         }
        }
        else
        {
             # print "\t\t$var1\n";
        }
    }
}

prunecheck(\%newbase, \%newhash);