$tagstack{requirements}->[1] = {
   text       => "A node name",
   attributes => {contactname   => "Jane Smith",
                  contactnumber => "555-1212"
                  }
}

##</code><code>##

#!/usr/bin/perl -wT

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

my $data = XML::Simple::XMLin('./test.xml');
# show what we start with
print Data::Dumper::Dumper($data);
my %tagstack;
my @temp;
foreach my $h (@{$data->{requirement}}) {
    my %t;
    $t{text} = $h->{content};
    delete $h->{content};
    $t{attributes} = $h;
    push @temp, \%t;
}
$tagstack{requirement} = \@temp;
# show the finished product
print Data::Dumper::Dumper(\%tagstack);

##</code><code>##

<root>
<requirement contactname="Joe Average">A power cord.</requirement>
<requirement contactname="Jane Smith" contactnumber="555-1212">A node name</requirement>
</root>

##</code><code>##

$VAR1 = {
          'requirement' => [
                             {
                               'contactname' => 'Joe Average',
                               'content' => 'A power cord.'
                             },
                             {
                               'contactnumber' => '555-1212',
                               'contactname' => 'Jane Smith',
                               'content' => 'A node name'
                             }
                           ]
        };
$VAR1 = {
          'requirement' => [
                             {
                               'text' => 'A power cord.',
                               'attributes' => {
                                                 'contactname' => 'Joe Average'
                                               }
                             },
                             {
                               'text' => 'A node name',
                               'attributes' => {
                                                 'contactnumber' => '555-1212',
                                                 'contactname' => 'Jane Smith'
                                               }
                             }
                           ]
        };