use strict;
use warnings;
use Benchmark 'cmpthese';

my $string = map { ('a'..'z')[rand 26] } 1..30;
my @sub_fields;
cmpthese( -1, {
	       regex1 => sub { @sub_fields = $string =~ /\w{5}/g },
	       regex2 => sub { @sub_fields = $string =~ /.{5}/g },
	       unpack => sub { @sub_fields = unpack '(A4)*', $string },
	       substr => sub { @sub_fields = map { substr $string, 5*$_, 5 } 0..length( $string )/5-1 },
	      });