I read some of the other postings here but didn't find anything that addresses my need. I am *very* remedial in perl but trying to learn quickly as my job description now requires it.

-I have a short script that uses List::Permutor to generate permutations of a series. Works great and prints to an outfile. -I also have a short script that open the .txt file containing all permutations, selects unique sequences from the list, and prints the unique sequences to a new outfile.

With small series this works great, but with long series I can't complete both steps because of my computer runs out of RAM (8GB). In fact, with 12! permutations, the computer runs sluggish just to open the outfile. I thought that if I could combine the two steps to run with only 1 outfile to worry about it might save me some memory.

I have posted my code below. Thanks for your help and time!

FIRST
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#!/usr/bin/perl<br>

use strict; 
use warnings;

use List::Permutor;


my $OutFile = '>permutations.txt';
open(OUTFILE, $OutFile) or die "The file $OutFile could not be found.\
+n";

my $word = 'aabc';
my $perm = new List::Permutor split(//,$word);

while  (my @set = $perm->next) {
    #print @set
     for(my $i=0; $i<length($word)-1; $i=$i+1) {
         my $letter = $set[$i];
         print OUTFILE "$letter,";
     };
     my $letter = $set[length($word)-1];
     print OUTFILE "$letter\n";
}
close (OUTFILE);
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SECOND
-----------------------

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

chdir('//Users/laptop/Desktop/') or die ("Sorry could not change to th
+e 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 $UniqPermut
+ations 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);
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