$ perl -le '$s="1234567890"x20;@s=split(/(.){70}/,$s);
   print length($s);print scalar @s;print join("\n",@s)'
200
5

0

0
123456789012345678901234567890123456789012345678901234567890

##</code><code>##

$ perl -le '$s="1234567890"x20;@s=split(/(.{70})/,$s);
   print length($s);print scalar @s;print join("\n",@s)'
200
5

1234567890123456789012345678901234567890123456789012345678901234567890

1234567890123456789012345678901234567890123456789012345678901234567890
123456789012345678901234567890123456789012345678901234567890

##</code><code>##

split /(?<=.{70})(.{70})/  # pos.look-behind for 70 chars, then capture 70

##</code><code>##

$ perl -le '$s="1234567890"x20;@s=split(/(?<=.{70})(.{70})/,$s);
   print length($s);print scalar @s;print join("\n",@s)'
200
3
1234567890123456789012345678901234567890123456789012345678901234567890
1234567890123456789012345678901234567890123456789012345678901234567890
123456789012345678901234567890123456789012345678901234567890