$ perl -we '
> my @values = 1..10;
> my $max    = 3;
> while ( my @parts = splice(@values, 0, $max) ) {
>   print join ", ", @parts, ( $#parts == 2 ? "\n" : () );
> }
> print "\n";
> '
1, 2, 3,
4, 5, 6,
7, 8, 9,
10