Why then did you not bother to write a few lines like:
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 },
});
that already shows that the regex idea is vastly inferior:
Rate substr unpack regex1 regex2
substr 696486/s -- -57% -94% -94%
unpack 1603093/s 130% -- -85% -86%
regex1 10731041/s 1441% 569% -- -4%
regex2 11165392/s 1503% 596% 4% --