#!/usr/bin/perl -w

$format = "Aa!Ff!";
$data = "1234567890";

$i = 0;
print map
{
   ($l = $_ % 32) &&
   $_ > 95 ? substr($data, ($i += $l) - $l, $l)
           : ($_ > 63 ? " " : "\n") x $l
} unpack "C*", $format;