use MCE::Flow; my $input1 = shift @ARGV; my @lengths; mce_flow_f { chunk_size => '2m', max_workers => 'auto', gather => \@lengths }, sub { my ($mce, $chunk_ref, $chunk_id) = @_; my (@chunk_lengths); chomp @{ $chunk_ref }; foreach (@{ $chunk_ref }) { push @chunk_lengths, length $_ unless />/; } MCE->gather(@chunk_lengths); }, $input1; MCE::Flow::finish; print scalar @lengths, "\n";