[Perl]XML

XML::Simple を使って Perl で XML を操作する。
読み込み
Example: part1.xml

<config>
  <user>Freddy</user>
  <passwd>hogehoge</passwd>
  <books>
    <book author="Ernest Miller Hemingway" title="The Old Man and the Sea"/>
    <book author="Mark Twain" title="The Adventures of Tom Sawyer"/>
  </books>
</config>

Example: part1.pl

use strict;
use utf8;
use XML::Simple;
use Data::Dumper;

print Dumper (XML::Simple->new()->XMLin());
my $config = XML::Simple->new()->XMLin();
print "user:" . $config->{user} . "\n";
print "password: " . $config->{passwd} . "\n";
print "book[0].author: " . $config->{books}->{book}[0]->{author} . "\n";
print "book[0].title: " . $config->{books}->{book}[0]->{title} . "\n";

XML ファイル, Perl スクリプトのファイル名を part1 としておくことで自動的にスクリプトから part1.xml を読み込んでくれる。

>perl part1.pl
could not find ParserDetails.ini in C:/usr/Perl/site/lib/XML/SAX
$VAR1 = {
  'passwd' => 'hogehoge',
  'user' => 'Freddy',
  'books' => {
    'book' => [
      {
        'title' => 'The Old Man and the Sea',
        'author' => 'Ernest Miller Hemingway'
      },
      {
        'title' => 'The Adventures of Tom Sawyer',
        'author' => 'Mark Twain'
      }
    ]
  }
};

user:Freddy
password: hogehoge
book[0].author: Ernest Miller Hemingway
book[0].title: The Old Man and the Sea

書き込み
Example: part2.pl

use strict;
use utf8;
use XML::Simple;
use Data::Dumper;

print Dumper (XML::Simple->new()->XMLin("part1.xml"));
my $simple = XML::Simple->new();
my $config = $simple->XMLin("part1.xml");
print "user:" . $config->{user} . "\n";
print "password: " . $config->{passwd} . "\n";
print "book[0].author: " . $config->{books}->{book}[0]->{author} . "\n";
print "book[0].title: " . $config->{books}->{book}[0]->{title} . "\n";
$config->{passwd} = "new_password";
$simple->XMLout($config,
OutputFile => 'output.xml',
XMLDecl => "");

このスクリプトを実行すると以下の output.xml が生成される
Example: output.xml

<?xml version='1.0'?>
<opt passwd="new_password" user="Freddy">
  <books>
    <book author="Ernest Miller Hemingway" title="The Old Man and the Sea" />
    <book author="Mark Twain" title="The Adventures of Tom Sawyer" />
  </books>
</opt>