summarize frequency

#!/usr/bin/perl
use strict;
use warnings;
open my $in, '<', 'test.txt' or die;
my $freq = [];
my $word = [];
while (<$in>) {
  chomp;
  my @line = split ',';
  push @$word, @line;
  for (my $i = 0; $i <= $#line; ++$i) {
    $freq->[$i] or $freq->[$i] = {};
    ++$freq->[$i]->{$line[$i]};
  }
}
close $in;
my %h = map { $_ => 1 } @$word;
my @uniq_word = sort keys %h;
my $all = {};
for (my $i = 0; $i < @$freq; ++$i) {
  print "column $i\n";
  for (@uniq_word) {
    $freq->[$i]->{$_} or $freq->[$i]->{$_} = 0;
    $all->{$_} or $all->{$_} = 0;
    $all->{$_} += $freq->[$i]->{$_};
    print "$_ = $freq->[$i]->{$_}\n";
  }
}
print "all\n";
print "$_ = $all->{$_}\n" for (@uniq_word);