#!/usr/bin/perl
use strict;
use warnings;

sub hd { join ' ', map sprintf("%02X", ord $_), split //, $_[0] }

my $str = "abcbadddd";
my $rts = reverse $str;

for my $rotate_count ( 0 .. length( $str ) - 1 ) {
	my $mask = $str ^ $rts;

	# turn all non-nulls to 0xFF for demonstration purposes
	$mask =~ tr/\1-\377/\377/;

	# to distinguish adjacent palindromes
	substr $mask, $rotate_count, 0, "\1";

	while( $mask =~ /\0{3,}/g ) {
		my $len = $+[0] - $-[0];
		my $offs = $-[0];
		--$offs if $offs > $rotate_count; # compensate for marker
		print substr( $str, $offs, $len ), "\n";
	}

	print "$rotate_count: ", hd( $str ), " ^ ", hd( $rts ), " = ", hd( $mask ), "\n";
	substr $rts, 0, 0, chop $rts;
}