Count the frequency of values on standard input

count

#!/usr/bin/perl -w
my %buckets;
while(<>) {
  chomp;
  unless (defined $buckets{$_}) {
    $buckets{$_} = 1;
  } else {
    $buckets{$_}++;
  }
}
while(($key, $val) = each(%buckets)) {
  printf "%5d %s\n",$val,$key;
}