use strict;
use warnings;

use XML::Checker::Parser;

my %expat_options =
  ( KeepCDATA => 1, Handlers => {Unparsed => \&my_Unparsed_handler} );
my $parser = new XML::Checker::Parser(%expat_options);

open OUT, '>', 'fail.xml';
print OUT <<OUT;
<!DOCTYPE a [
    <!ELEMENT a (b,c)>
    <!ELEMENT b (#PCDATA)>
    <!ELEMENT c (#PCDATA)>
]>
<a>
"something should not be here"
<b></b>
<c></c>
</a>
OUT
close OUT;

eval {
    local $XML::Checker::FAIL = \&my_fail;
    $parser->parsefile("fail.xml");
};

if ($@) {
    print $@;
} else {
    print "xml has been validated";
}

sub my_fail {
    my $code = shift;
    die XML::Checker::error_string( $code, @_ ) if $code < 200;
    XML::Checker::print_error( $code, @_ );
}