use strict;
use warnings;

my $val = 0;
p('Zero');
$val |= 1;
p('Or-ed 1');
$val <<= 1;
p('shift 1');
$val |= 0;
p('Or-ed 0');
$val <<= 1;
p('shift 1');
$val |= 1;
p('Or-ed 1');
$val <<= 1;
p('shift 1');
$val |= 0;
p('Or-ed 0');

#Prints in binary with lowest bit to the right side.
sub p
{
printf '%20s : %4d => ', shift, $val;
print reverse split '', unpack'b*', pack'c', $val;
print "\n";
}