use strict;
use warnings;

my $i = 0;
my $size = 10;
my $string = 'some long string';
my @substrings;
my $len = length($string);

while($i <= $len) {
	push(@substrings, substr($string, $i, $size));
	$i += $size;
}

$" = "\n";
print "@substrings\n";