Counting underscore prefixed packages

count_under.pl

use 5.012;
use strict;
use warnings;

$|=1;

my $start;

while (<>) {
  chomp;
  if ( !$_ ) {
    $start = 1;
    next;
  }
  next if !$start;
  my ($pack,$ver,$dist) = split ' ';
  my @packs = split m!\:\:|\'!, $pack;
  say $_ if grep { m!^\_! } @packs;
}