Extracting a multiple level XML using Perl

I'm trying to extract data from an XML file.

The format of the XML is as follows:

<notifications>
<notification name="ccmSmtp" oid="1.3.6.1" status="current">
  <objects>
    <object module="callhome" name="ccmSmtp"/>
  </objects>
  <description>
     This is a d开发者_如何学Goescription
  </description>
</notification>
<notification name="ccmAlertGroup" oid="1.3.6.1" status="current">
  <objects>
    <object module="callhome" name="callHome"/>
  </objects>
  <description>
       This is a description
  </description>
</notification>
<notification name="ccmAlert" oid="1.3.6.1" status="current">
  <objects>
    <object module="callhome" name="callHome"/>
  </objects>
  <description>
    This is a description
  </description>
</notification>
<notification name="ccmSmtp" oid="1.3.6.1" status="current">
  <objects>
  </objects>
  <description>
      This is a description
  </description>
</notification>
</notifications>

I have written the following code to extract the notifications node from example.xml file.

#!/usr/bin/perl

use XML::Simple;
use Data::Dumper;

$xml = new XML::Simple;

$data = $xml->XMLin("example.xml",KeyAttr => {
  notifications => notification => 'name'
});

$notification = $data->{notifications};

print Dumper($notification);

When I run the above Perl file I get the following output:

$VAR1 = {
  'notification' => [
      {
        'objects' => {
          'object' => {
            'name' => 'ccmSmtp',
            'module' => 'callhome'
          }
        },
        'status' => 'current',
        'oid' => '1.3.6.',
        'name' => 'ccmSmtp',
        'description' => ' This is a mib '
      },
      {
        'objects' => {
          'object' => {
            'name' => 'callHome',
            'module' => 'module'
          }
        },
        'status' => 'current',
        'oid' => '1.3.6.1.4',
        'name' => 'ccmAlert',
        'description' => 'This is a description'
      },
      {
        'objects' => {
          'object' => {
            'name' => 'callHome',
            'module' => 'homemib'
          }
        },
        'status' => 'current',
        'oid' => '1.3.6.1.4',
        'name' => 'ccmAlertf',
        'description' => 'This is a description'
      },
      {
        'objects' => {},
        'status' => 'current',
        'oid' => '1.3.6.1',
        'name' => 'ccmSmtp',
        'description' => ' This is an example'
      }
    ]
};

My question is, how can I extract the contents of notification node and store the values in separate variables/array ?

Generally for extracting items from XML I would start with XPath. There is an XPath package for Perl, probably even in the XML package you're already using.

$notification is just a ref to a hash with one key 'notification' that has an array of hashes.

You could loop through it by doing

for my $n ( @{$notification->{notification}} ) {
    # ie. to get status out, this is same for description,oid,name
    my $status = $n->{status};

    # To get the nested 'objects' data object module value (phew)
    my $object_module = $n->{status}{object}{module};

}

I am unclear what it is you want. The code you posted did not produce that output as it will not compile, but if you wrote instead

my $data = $xml->XMLin("x.xml", KeyAttr => ['notification']);
print Dumper $data;

then you would get exactly that. Now $data->{notification} is a reference to an array of four hashes (corresponding to the four elements) which can be accessed as

my $note0 = $data->{notification}[0];

etc. Does this answer your question?

I would looped like below :

foreach $NOTIFICATION( @{$data->{'notification}}) 
{   
foreach $OBJECT (@{$NOTIFICATION->{'OBJECT'}}) 
{
$name=$NOTIFICATION->{'name'};                                 $module=$OBJECT->{'module'}; 

Print $name , $module 
}
}