$ curl -sS https://archive.apache.org/dist/xerces/p/ | grep -oE 'XML-Xerces[^"<]*' | sort -u
XML-Xerces-2.7.0-0.tar.gz
XML-Xerces-2.7.0-0.tar.gz.asc

Revision history for Perl extension XML::Xerces.

2.7.0-0 Sun Jan  1 08:44:27 IST 2006
	- first public 2.7 release
	- working with SWIG-1.3.28 pre-release
	- removed all uses of XMLString::transcode() from the Perl
	  callback handler classes in Handler/

2.6.0-2
	- first public 2.6 release
	- all known memory leaks fixed
	...

# cpanm -v XML::Xerces
You have not defined any of the following environment variables:
   XERCESCROOT
   XERCES_LIB
   XERCES_INCLUDE
...
Couldn't find XercesVersion.hpp in your include directory  at Makefile.PL line 188.
! Configure failed for XML-Xerces-2.7.0-0. See /root/.cpanm/work/1792134263.10400/build.log for details.

$ cd /root/XML-Xerces-2.7.0-0 && ls -la
total 2784
drwxr-xr-x 10 1000  1000    4096 Mar 14  2006 .
-rw-r--r--  1 1000  1000   11572 Jan  1  2006 Changes
-rw-r--r--  1 1000  1000    2802 Dec 20  2005 FAQ
-rw-r--r--  1 1000  1000    1053 Dec 20  2005 INSTALL
-rw-r--r--  1 1000  1000    9939 Mar 10  2006 Makefile.PL
-rw-r--r--  1 1000  1000   13835 Dec 20  2005 README
-rw-r--r--  1 1000  1000 2382945 Mar 13  2006 Xerces.cpp
-rw-r--r--  1 1000  1000    4581 Mar 13  2006 Xerces.i
-rw-r--r--  1 1000  1000  244206 Mar 13  2006 Xerces.pm
drwxr-xr-x  3 1000  1000    4096 Mar 14  2006 interface
drwxr-xr-x  2 1000  1000    4096 Mar 14  2006 samples
drwxr-xr-x  2 1000  1000    4096 Mar 14  2006 scripts
drwxr-xr-x  2 1000  1000    4096 Mar 14  2006 t
...

$ grep -h '%include "xercesc' interface/*.i | sort -u | wc -l
95
$ grep -h '%include "xercesc' interface/*.i | sort -u | head -14
%include "xercesc/dom/DOMAttr.hpp"
%include "xercesc/dom/DOMBuilder.hpp"
%include "xercesc/dom/DOMCDATASection.hpp"
%include "xercesc/dom/DOMCharacterData.hpp"
%include "xercesc/dom/DOMComment.hpp"
%include "xercesc/dom/DOMDocument.hpp"
%include "xercesc/dom/DOMDocumentFragment.hpp"
%include "xercesc/dom/DOMDocumentRange.hpp"
%include "xercesc/dom/DOMDocumentTraversal.hpp"
%include "xercesc/dom/DOMDocumentType.hpp"
%include "xercesc/dom/DOMElement.hpp"
%include "xercesc/dom/DOMEntity.hpp"
%include "xercesc/dom/DOMEntityReference.hpp"
%include "xercesc/dom/DOMEntityResolver.hpp"

#!/usr/bin/perl -w

package MyErrorHandler;
use strict;
@ISA = qw(XML::Xerces::PerlErrorHandler);
sub warning {
  my $line = $_[1]->getLineNumber;
  my $column = $_[1]->getColumnNumber;
  my $message = $_[1]->getMessage;
  printf STDERR "%s:[%s]:%d:%d:%s:%s\n",
    $main::PROGRAM,$main::FILE,$line, $column, 'W', $message;
}

sub error {
  ... 同样通过 getLineNumber/getColumnNumber/getMessage 组装报错行
}

sub fatal_error { ... }
1;

package main;
use strict;
use XML::Xerces;

$ grep -c '=item' Xerces.pm
0
$ grep -c '=head' Xerces.pm
0

# apt-get install -y libxml-libxml-perl
...
# perl -MXML::LibXML -e 'printf "XML::LibXML %s (libxml2 %s)\n", $XML::LibXML::VERSION, XML::LibXML::LIBXML_VERSION()'
XML::LibXML 2.0134 (libxml2 20912)

<?xml version="1.0" encoding="UTF-8"?>
<catalog xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="books.xsd">
  <book id="bk001" lang="zh">
    <title>XML 实战</title>
    <author>张三</author>
    <price currency="CNY">59.00</price>
  </book>
  <book id="bk002" lang="en">
    <title>Learning XML</title>
    <author>Eric Ray</author>
    <price currency="CNY">79.50</price>
  </book>
</catalog>

<!ELEMENT catalog (book+)>
<!ELEMENT book (title, author, price)>
<!ELEMENT title (#PCDATA)>
<!ELEMENT author (#PCDATA)>
<!ELEMENT price (#PCDATA)>
<!ATTLIST book id   CDATA #REQUIRED
               lang CDATA #REQUIRED>
<!ATTLIST price currency CDATA #REQUIRED>

use strict; use warnings;
use open ':std', ':encoding(UTF-8)';
use XML::LibXML;
my $doc = XML::LibXML->load_xml(location => $ARGV[0]);
my $root = $doc->documentElement;
printf "root element: %s\n", $root->nodeName;
for my $book ($doc->findnodes('/catalog/book')) {
    my $id   = $book->getAttribute('id');
    my $t    = $book->findvalue('title');
    my $p    = $book->findvalue('price');
    print "book $id: $t (price=$p)\n";
}
print "first book lang: ", $doc->findvalue('/catalog/book[1]/@lang'), "\n";
my $n = $doc->findvalue('count(/catalog/book)');
print "total books: $n\n";

root element: catalog
book bk001: XML 实战 (price=59.00)
book bk002: Learning XML (price=79.50)
first book lang: zh
total books: 2

use strict; use warnings;
use XML::LibXML;
my $doc = XML::LibXML->createDocument('1.0', 'UTF-8');
my $cat = $doc->createElement('catalog');
$doc->setDocumentElement($cat);
for my $i (1..2) {
    my $b = $doc->createElement('book');
    $b->setAttribute(id => "bk10$i");
    $b->setAttribute(lang => 'zh');
    $b->appendTextChild(title => "Perl 与 XML 第${i}版");
    my $p = $doc->createElement('price');
    $p->setAttribute(currency => 'CNY');
    $p->appendText(sprintf "%.2f", 45.0 + $i);
    $b->appendChild($p);
    $cat->appendChild($b);
}
$doc->toFile('/root/libxml-created.xml', 1);
print $doc->toString(1);

<?xml version="1.0" encoding="UTF-8"?>
<catalog>
  <book id="bk101" lang="zh">
    <title>Perl 与 XML 第1版</title>
    <price currency="CNY">46.00</price>
  </book>
  ...（bk102 条目结构相同：title 为 "Perl 与 XML 第2版"、price 47.00，略）
</catalog>

use strict; use warnings;
use open ':std', ':encoding(UTF-8)';
use XML::LibXML;
my ($xml, $dtdf) = @ARGV;
my $doc = XML::LibXML->load_xml(location => $xml, { recover => 0 });
my $dtd = XML::LibXML::Dtd->new('', $dtdf);
eval { $doc->validate($dtd) };
if ($@) { print "$xml: INVALID\n$@" } else { print "$xml: VALID\n" }

# perl /root/libxml-dtd.pl /root/xmldemo/books.xml /root/xmldemo/books.dtd
/root/xmldemo/books.xml: INVALID
/root/xmldemo/books.xml:0: validity error : No declaration for attribute noNamespaceSchemaLocation of element catalog
/root/xmldemo/books.xml:0: validity error : No declaration for attribute xmlns:xsi of element catalog

# perl /root/libxml-dtd.pl /root/xmldemo/books-dtd.xml /root/xmldemo/books.dtd
/root/xmldemo/books-dtd.xml: VALID

# perl /root/libxml-dtd.pl /root/xmldemo/books-bad.xml /root/xmldemo/books.dtd
/root/xmldemo/books-bad.xml: INVALID
...（前两行与上文相同的 xsi 属性报错，略）
/root/xmldemo/books-bad.xml:0: validity error : Element book content does not follow the DTD, expecting (title , author , price), got (title price )

use strict; use warnings;
use open ':std', ':encoding(UTF-8)';
use XML::LibXML;
my ($xml, $xsdf) = @ARGV;
my $doc = XML::LibXML->load_xml(location => $xml, { recover => 0 });
my $schema = XML::LibXML::Schema->new(location => $xsdf);
eval { $schema->validate($doc) };
if ($@) { print "$xml: INVALID\n$@" } else { print "$xml: VALID\n" }

# perl /root/libxml-xsd.pl /root/xmldemo/books.xml /root/xmldemo/books.xsd
/root/xmldemo/books.xml: VALID
# perl /root/libxml-xsd.pl /root/xmldemo/books-bad.xml /root/xmldemo/books.xsd
/root/xmldemo/books-bad.xml: INVALID
/root/xmldemo/books-bad.xml:0: Schemas validity error : Element 'price': This element is not expected. Expected is ( author ).

use strict; use warnings;
use XML::LibXML::Reader;
my $reader = XML::LibXML::Reader->new(location => $ARGV[0]) or die "cannot open $ARGV[0]\n";
my $books = 0;
while ($reader->read) {
    if ($reader->nodeType == XML_READER_TYPE_ELEMENT && $reader->name eq 'book') {
        $books++;
        my $id = $reader->getAttribute('id') // '';
        print "element book id=$id\n";
    }
}
print "pull-parse done, book elements: $books\n";

element book id=bk001
element book id=bk002
pull-parse done, book elements: 2