0: # for those times when Perl's built-in sort is just too fast
1: 
2: use strict;
3: 
4: my @data = qw(7 6 5 4 3 2 1 0) ;
5: 
6: rpsort(\@data);
7: print "$_\t" foreach (@data);
8: 
9: exit;
10: 
11: # a random permutation sort
12: # ref. Perl Cookbook recipe 4.17 for the shuffle
13: 
14: sub rpsort {
15: 	my $list = shift;
16: 	my ($k,$j);
17: 
18: try_again:
19: 	for ($j = @$list; --$j; ) {
20: 		$k = int rand($j+1);
21: 		next if ($j == $k);
22: 		@$list[$j, $k] = @$list[$k, $j];
23: 	}
24: 
25: 	for ($j = 0 ; $j < (@$list -1); $j++) {
26: 		goto try_again if (@$list[$j] > @$list[$j+1]);
27: 	}
28: }