Print by N pages, first even then odd pages

print-by-n-pages-even-odd.pl

perl -le '$pages=3; $start=7; $end=104; for $a (0..$end-$start) { push @even, $a+$start if $a % ($pages*2) < $pages; push @odd, $a+$start if $a % ($pages*2) >= $pages }; for $a (0..(length @even)-1) { print join ",", grep {defined} @even[(0+$a*$pages*10)..(($pages*10-1)+$a*$pages*10)]; }; print; for $a (0..(length @odd)-1) { print join ",", grep {defined} @odd[(0+$a*$pages*10)..(($pages*10-1)+$a*$pages*10)]; }'