use strict;
use warnings;
use feature 'say';
#~ use Say; #portability trick for 5.8.8
use XML::SAX::ParserFactory;
use XML::SAX::Writer;

my $input = $ARGV[0] or die "usage: $0 <file.xml> [parser_package]";
$XML::SAX::ParserPackage = $ARGV[1] if $ARGV[1];

my $output; #just for not outputting to STDOUT

my $writer = new XML::SAX::Writer(Output => \$output);
my $handler = new SaxHandler( Handler => $writer );
my $parser = XML::SAX::ParserFactory->parser( Handler => $handler );

say sprintf "parser is %s (%s)", ref $parser, $parser->VERSION ;
$parser->parse_file($input);

{
    package SaxHandler;
    use base 'XML::SAX::Base';
    use Data::Printer {indent=>2};
    use feature 'say';
    #~ use Say; #portability trick for 5.8.8
    
    sub xml_decl {
        my ($self, $decl) = @_;
        say "decl ", np $decl;
        $self->SUPER::xml_decl($decl);
    }
    
    sub start_document {
        my ($self, $doc) = @_;
        say "document ", np $doc;
        $self->SUPER::start_document($doc);
    }
    
    sub start_element {
        my ($self, $el) = @_;
        #~ say "start element " . $el->{LocalName};
        $self->SUPER::start_element($el);
    }
}