Another way is to use List::MoreUtils::natatime.

use warnings;
use strict;
use List::MoreUtils qw(natatime);

my @nums = 1 .. 30;
my $it = natatime(7, @nums);
while (my @vals = $it->()) {
    print join(',', @vals), "\n";
}

__END__

1,2,3,4,5,6,7
8,9,10,11,12,13,14
15,16,17,18,19,20,21
22,23,24,25,26,27,28
29,30
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