Found in /opt/perl/snap/lib/5.8.0/pods/perlfaq4.pod
  How do I shuffle an array randomly?
            If you either have Perl 5.8.0 or later installed, or if you have
            Scalar-List-Utils 1.03 or later installed, you can say:

                use List::Util 'shuffle';

                    @shuffled = shuffle(@list);

            If not, you can use a Fisher-Yates shuffle.

                sub fisher_yates_shuffle {
                    my $deck = shift;  # $deck is a reference to an array
                    my $i = @$deck;
                    while ($i--) {
                        my $j = int rand ($i+1);
                        @$deck[$i,$j] = @$deck[$j,$i];
                    }
                }

                # shuffle my mpeg collection
                #
                my @mpeg = <audio/*/*.mp3>;
                fisher_yates_shuffle( \@mpeg );    # randomize @mpeg in place
                print @mpeg;

            Note that the above implementation shuffles an array in place,
            unlike the List::Util::shuffle() which takes a list and returns
            a new shuffled list.

            You've probably seen shuffling algorithms that work using
            splice, randomly picking another element to swap the current
            element with

                srand;
                @new = ();
                @old = 1 .. 10;  # just a demo
                while (@old) {
                    push(@new, splice(@old, rand @old, 1));
                }

            This is bad because splice is already O(N), and since you do it
            N times, you just invented a quadratic algorithm; that is,
            O(N**2). This does not scale, although Perl is so efficient that
            you probably won't notice this until you have rather largish
            arrays.