Don't know of a module, but if you are just looking at strings, the following code would work, printing each generated possibility only once: 

#
# Assumes $word and $desired_length previously defined.
#
my @characters = split('', $word);
my (%found);
&gen_nofm(\@characters, \%found, '', $desired_length);
print($_, "\n")    
  foreach (sort({lc($a) cmp lc($b)} keys(%found)));

sub gen_nofm 
{
    my ($charlist, 
      $found_thusly, 
      $partial_word, 
      $desired_length) = @_;
    if ($desired_length) 
    {
        for (my $index = 0; 
          $index < scalar(@{$charlist}); 
          $index++) 
        {
            &gen_nofm($charlist, 
              $found_thusly, 
              $partial_word . ${$charlist}[$index], 
              $desired_length - 1);
        }
    }
    else 
    {
        ${$found_thusly}{$partial_word}++;
    }
}

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In reply to Re: N Permutations of M Items by atcroft
in thread N Permutations of M Items by mt2k

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