perl根据条件从xml文件解析特定值

Question

有人可以告诉我如何从xml文件解析出特定信息吗？我想用正则表达式吗？

我正在使用XML::Simple来查看我的test.xml文件。

例如，我要搜索的字符串test-out-00000，如果它存在，那么给我/打印size = 135860644

数据：

$VAR1 = { 
      'recursive' => 'no', 
      'version' => '0.20.202.1.1101050227', 
      'time' => '2011-09-30T02:49:39+0000', 
      'filter' => '.*', 
      'file' => { 
        'owner' => 'test_act', 
        'replication' => '3', 
        'blocksize' => '134217728', 
        'permission' => '-rw-------', 
        'path' => '/source/feeds/customer/test/test-out-00000', 
        'modified' => '2011-09-30T02:48:41+0000', 
        'size' => '135860644', 
        'group' => '', 
        'accesstime' => '2011-09-30T02:48:41+0000' 
        }, 
      'path' => '/source/customer/test', 
      'directory' => { 
         'owner' => 'test_act', 
         'group' => '', 
         'permission' => 'drwx------', 
         'path' => '/source/feeds/customer/test', 
         'accesstime' => '1970-01-01T00:00:00+0000', 
         'modified' => '2011-09-30T02:48:41+0000' 
         }, 
      'exclude' => '' 
     }; 
recursive:no 
version:0.20.202.1.1101050227 
time:2011-09-30T02:49:39+0000 
filter:.* 
file:HASH(0x84c841c) 
path:/source/customer/test 
directory:HASH(0x84c7648) 
exclude: 

工作perl脚本：

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

my $xml = $ARGV [0]; 
my $data = XMLin($xml); 
print Dumper($data); 

foreach my $attributes (keys %{$data}){ 
    print"$attributes:${$data}{$attributes}\n"; 
} 

XML文件test.xml：

<?xml version="1.0" encoding="UTF-8"?> 
<listing time="2011-09-30T02:49:39+0000" recursive="no" path="/source/customer/test" exclude="" filter=".*" version="0.20.202.1.1101050227"> 
<directory path="/source/feeds/customer/test" modified="2011-09-30T02:48:41+0000" accesstime="1970-01-01T00:00:00+0000" permission="drwx------" owner="test_act" group=""/> 
<file path="/source/feeds/customer/test/test-out-00000" modified="2011-09-30T02:48:41+0000" accesstime="2011-09-30T02:48:41+0000" size="135860644" replication="3" blocksize="134217728" permission="-rw-------" owner="test_act" group=""/> 
</listing> 

Answer 1

我假设你一直在寻找文件名中的文本字符串？如果是这样，这是做的一种方式：

use strict; 
use warnings; 
use XML::Simple; 

my $xml = $ARGV [0]; 
my $data = XMLin($xml); 

my $size = 0;  

if (exists $data->{file}->{path} and $data->{file}->{path} =~ /test-out-00000/) { 
    $size = $data->{file}->{size}; 
} 

如果您的数据格式如下，你也可以使用XML ::的libxml只获取使用XPath表达式的值。