use strict;
use warnings;
use feature 'say';
#~ use utf8;
use XML::SAX::ParserFactory;

$|++;

#to force one kind of parser for ParserFactory->parser()
#~ $XML::SAX::ParserPackage = "XML::SAX::PurePerl";
#~ $XML::SAX::ParserPackage = "XML::SAX::Expat"; #no xml_decl
#~ $XML::SAX::ParserPackage = "XML::SAX::ExpatXS";
#~ $XML::SAX::ParserPackage = "XML::LibXML::SAX";
$XML::SAX::ParserPackage = "XML::LibXML::SAX::Parser";

{
    package MySax;
    use feature 'say';
    use Devel::Peek;

    sub new {
        my $class = shift;
        return bless {}, $class;
    }

    sub hexprint {
        my ($self, $data) = @_;
        join ' ', map { sprintf '%02X', $_ } unpack 'C*', $data;
    }
    
    sub characters {
        my ($self, $data) = @_;
        my $content = $data->{Data};
        say "characters for elt: ". $content;
        say "bytes for elt: ". $self->hexprint($content);
        Dump($content);
    }
}

my $handler = new MySax;
my $parser = XML::SAX::ParserFactory->parser(Handler => $handler);
say "parser is " . ref $parser;
say "file: " . $ARGV[0] if $ARGV[0];
$parser->parse_file($ARGV[0] // *DATA);

__DATA__
<empty/>