Question

Can someone show me how to parse out specific information from an xml file? Am I suppose to use a regex?

I am using XML::Simple to view my test.xml file.

For example, I want to search for the string test-out-00000, if it exists then give me/print the size = 135860644

Data:

$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:

Working perl script:

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 file 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

I’m assuming you’re always looking for the text string in the filename? If so, this is one way of doing it:

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};
}

If your data follows this format you could also use XML::LibXML to just grab the values using an XPATH expression.