sub bukShuffle {
    my( $r, $t );
    $r = $_ + rand( @array - $_ ),
    $t =           $array[ $_ ],
    $array[ $_ ] = $array[ $r ],
    $array[ $r ] = $t
    for 0 .. $#array;
}

##</code><code>##

my %h;
bukShuffle( @array = qw[a b c d ] ), ++$h{ join ' ', @array } for 1 .. 1e6;

pp %h;


##</code><code>##

[19:07:24.88] C:\test>junk50
(
  "c a d b",  41868,
  "a d b c",  41833,
  "b d a c",  41554,
  "d a c b",  41772,
  "b c d a",  41671,
  "c d a b",  41779,
  "b d c a",  41783,
  "a b d c",  41724,
  "c b a d",  42012,
  "c a b d",  41571,
  "b c a d",  41270,
  "b a c d",  41192,
  "d c a b",  41443,
  "a b c d",  41669,
  "a c d b",  41884,
  "d b a c",  41786,
  "c b d a",  41608,
  "a d c b",  41598,
  "d c b a",  41544,
  "b a d c",  41578,
  "d b c a",  41684,
  "d a b c",  41672,
  "a c b d",  41622,
  "c d b a",  41883,
)