package StringInspector;

use Hash::Util qw(lock_keys);
use strict;

sub new {
	my $self = {};
	$self->{SUSPECT} = "";
	$self->{BYTES_IN_ROW} = 10;
	$self->{COLUMNS_BETWEEN_PANES} = 5;
	bless $self;
	lock_keys(%{$self});
	return $self;
}

sub inspect {
	my ($self, $string) = @_;
	$self->{SUSPECT} = $string;
}

sub bytes_in_row {
	my $self = shift;
	if (@_) {
		$self->{BYTES_IN_ROW} = shift;
	}
	return $self->{BYTES_IN_ROW};
}

sub columns_between_panes {
	my $self = shift;
	if (@_) {
		$self->{COLUMNS_BETWEEN_PANES} = shift;
	}
	return $self->{COLUMNS_BETWEEN_PANES};
}

sub display {
	use bytes;
	my $self = shift;
	for (my $index = 0; $index <= length $self->{SUSPECT}; $index += $self->{BYTES_IN_ROW}) {
		my ($numbers, $chars) = ("", "");
		foreach my $this_char (split(//, substr($self->{SUSPECT}, $index, $self->{BYTES_IN_ROW}))) {
			my $ascii = ord($this_char);
			$numbers .= sprintf("0x%0x  ", $ascii);
			$chars .= (($ascii >= 32) and ($ascii <= 126)) ? $this_char : "."; 
		}
		print $numbers;
		print " " x (6 * $self->{BYTES_IN_ROW} - length $numbers);
		print " " x $self->{COLUMNS_BETWEEN_PANES};
		print $chars;
		print "\n";
	}
}

1;


testing code:
use StringInspector;
use strict;
my $inspector = new StringInspector;
$inspector->bytes_in_row(3);
$inspector->columns_between_panes(40);
$inspector->inspect("abcdefghi" . chr(400) ."jkl");
$inspector->display();