#!/usr/bin/env perl 

use strict;
use warnings;
use MCE::Grep;
use Data::Dump;
use Time::HiRes qw (time);

MCE::Grep::init( { max_workers => 4 } );

my $start = time;

open( my $fh, '<', 'very_huge.file' );

my @result = mce_grep { /karl/ } $fh;

close $fh;

printf "Took %.3f seconds\n", time - $start;

dd \@result;

__END__

karls-mac-mini:monks karl$ ./huge.pl 
Took 29.690 seconds
["nose cuke karl\n"]