Question

Sorry for not being clear.
The problem I am trying to convey is that XML::Simple does not allow me direct access to the hash, I must refer to the key in question through the XML::Simple module. Using something like $xml->{key}.

Here is the code I am using and a copy of the hash output.

The reason this is a problem is because I need to construct a series of loops using the keys of the hash [seen below], and I cannot build a foreach loop with a hash referrence, when I tried it, perl gave me an error.

So what I am looking for is a module or solution to allow me to dump the contents of the XML file to a hash that I declare in my script. I also need the ability to write back out to an XML file.

#!/usr/bin/perl
use strict;
use warnings;
use XML::Simple;
use Data::Dumper;

system ("clear");

my $xml = XML::Simple->new;

# Using the XML::Simple object, read guest_os.xml to a hash

my $xml_file = $xml->XMLin('config.xml',

                SearchPath => './config',

                SuppressEmpty => 1);




$VAR1 = \{
        'esxi01' => {
                    'password' => 'myspoonistoobig!',
                    'user' => 'root',
                    'port' => '22'
                  },
        'esxi02' => {
                    'password' => 'myspoonistoobig!',
                    'user' => 'root',
                    'port' => '22'
                  },
        'Setup' => 'FALSE'
      };

For me to access a single key/values in the hash that is created [above] I have to use something like this.

$xml_file->{esxi01}{password}.

Oh yeah I forgot the actual XML file.

<Config>
  <esxi01>
    <password>password</password>
    <port>22</port>
    <user>root</user>
  </esxi01>
  <esxi02>
    <password>password</password>
    <port>22</port>
    <user>root</user>
  </esxi02>
  <Setup>FALSE</Setup>
</Config>

This is the simplest of the 3 or so I have.

Update:

The first part of the loop works with no problem, the problem happens when I try to use the second part of the loop.

Here is the way my code looks

my $xml = XML::Simple->new;

# Using the XML::Simple object, read guest_os.xml to a hash

my $xml_file = $xml->XMLin('config.xml',

                SearchPath => './config',

                SuppressEmpty => 1);

foreach my $server (keys %$xml_file) {
    foreach my $attribute (keys %{$xml_file->{$server}}) {
        print "$attribute\n";
    }
}

The output looks like this,

Can't use string ("password") as a HASH ref while "strict refs" in use at foreach_test line 21.

I have tried using quotes in several places to fix the problem but nothing seems to work.

Answer 1

I’m not sure if I understand what you need correctly – the question is very confusing. What you SEEM to be asking is:

• You have a complicated nested XML. E.g. <t1><t2><t3>value</t3></t2></t1>

• You seem to want to access contents of tag <t3> but without needing to go through the hash keys in a hash-of-hash-of… data structure that XML::Simple creates to represent the DOM. E.g. you don’t want to do $xml->{t1}->{t2}->{t3}.

If that’s the case, your problem is that you are using a DOM parser. A SAX parser (like XML::Twig) lets you execute events upon parsing specific tags, e.g. t3 no matter where in the sructure that tag is.

---

If your problem is that you just don’t know which tags exist (as keys in the hash),
you can do keys %$xml or keys %{ $xml->{t1} } to list them.

UPDATE

To loop using your example:

foreach my $key (keys %$xml) { # $key will be esxi01, etc...
    foreach my $attribute (keys %{ $xml->{$key} }) {
        "Key: $key; attribute: $attribute; value: $xml->{$key}->{$attribute}\n";
    }
    print "Port for $key: $xml->{$key}->{port}\n"; # Hardcoded
}

---

UPDATE2

The problem is in the <Setup>FALSE</Setup> XML tag. It has no subtags, so in the hash its value will be a SCALAR and not a hash. To fix, you need to check that the inner element is, indeed, a hash:

foreach my $server (keys %$xml_file) {
    next if (ref ($xml_file->{$server}) ne ref({})); # Not a hash
    foreach my $attribute (keys %{$xml_file->{$server}}) {
        print "$attribute\n";
    }
}