DOIT: while (my $it = $csv->getline ($io)) {
          my (%rec, %HoH, $p);
          # chomp;             # No need to chomp anymore!
          $t_counter++;
          # my @fields = @$it; # Don't make a copy
          if ($it->[0] =~ /^STOP/) { # use the reference
              :
              }
          elsif ($it->[0] ...