#!/usr/bin/perl
use warnings;
use strict;

chdir('//Users/laptop/Desktop/') or die ("Sorry could not change to the perl/programs directory.\n");

my $AllPermutations = 'permutations.txt'; #INFILE
open(ALLPERMUTATIONS, $AllPermutations) or die "File: $AllPermutations failed to open: $!\n";

my $UniqPermutations = '>unique_permutations.txt'; #OUTFILE
open(UNIQPERMUTATIONS, $UniqPermutations) or die "The file $UniqPermutations could not be found.\n";

my @AllPermutations = <ALLPERMUTATIONS>;

my %seen = ();
my @unique = grep { ! $seen{ $_ }++ } @AllPermutations;

print "@unique";
my $str = "@unique";
print join(",",split(//,$str));

close(ALLPERMUTATIONS);
close(UNIQPERMUTATIONS);