I would not call that a better fix. Adds unnecessary complexity and just confuses things. If you do insist that you do not want to have to pass the $move_disk around, it's cleaner to do it like this: 

{
    my $move_disk;
    sub hanoi {
        $move_disk = pop(@_);

        goto &_hanoi; # (almost) equivalent to _hanoi(@_)
    }
    sub _hanoi {
        my ( $n, $start, $end, $extra ) = @_;

        if ( $n == 1 )
        {
            $move_disk->( 1, $start, $end );
        }
        else
        {
            _hanoi( $n - 1, $start, $extra, $end );
            $move_disk->( $n, $start, $end );
            _hanoi( $n - 1, $extra, $end, $start );
        }
    };
}

hanoi( 3, 'A', 'B', 'C', sub {print "(@_)\n"} );

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Jenda
Enoch was right!
Enjoy the last years of Rome.

In reply to Re^2: passing subroutine references by Jenda
in thread passing subroutine references by joe76

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