If you want unique values think of hash keys

#!perl
use strict;
my @lines = ( ',,1,,one', ',,0,,zero' , ',,2,,two' );

# parse lines
my %uniq = ();
foreach (@lines) {
  my @fields = split /,/;
  if ( ($fields[2] eq '1') or ($fields[2] eq '0') ) {
    ++$uniq{$fields[4]};
  } 
}
print "$_\n" for sort keys %uniq;

# create fh
my $dir = '/tmp/loc/';
my %dmphash = ();
for (keys %uniq){
  my $file = $dir."$_.txt";
  open my $fh, '>', $file
     or die "Cannot open file '$file' for writing: $!";
  $dmphash{$_} = $fh;
}
[download]