$ perl -le'
my @array = (1, 2, 3, 4, 5, 6, 7, 8);
my @new_array = map{ [$array[2 * $_ - 1], $array[2 * $_]] } 1 .. @array/2;
use Data::Dumper; print Dumper \@new_array;
'
$VAR1 = [
          [
            2,
            3
          ],
          [
            4,
            5
          ],
          [
            6,
            7
          ],
          [
            8,
            undef
          ]
        ];