Perl: array de-reference

Question

I'm trying to figure out how to de-reference a value in an array but have hit a dead end, I've attempted to research the issue but need some help.

I'm grabbing some data from an infoblox database and trying to search within the results to find the mac address of a host entry, the data exists in the array as a hash generate by the following code:

use strict;
use Data::Dumper;
my @results = $session->get(
   object  => "Infoblox::DNS::Host",
   name    => "test.com.au",
   ipv4addrs   => ".*.",
   view    => "external"
);

I'm de-referencing at a high level of the data structure using '$_->ipv4addrs' then looping over the output using the following code:

foreach (@results) {
    my @search = $_->ipv4addrs;        
         foreach (@search) {
             print Dumper($_) . "\n";
    }
}

which prints the following output using Data::Dumper:

$VAR1 = [
      bless( {
               'network' => '111.111.111.0/25',
               'options' => [],
               'dynamic' => 'false',
               '__version' => '4.2r5-5-68691',
               'VIEW_FUNCTION' => {
                                    'remove' => '.com.infoblox.perl_api.Infoblox.DHCP.remove_fixed_address',
                                    'search' => '.com.infoblox.perl_api.Infoblox.DHCP.search_fixed_address',
                                    'add' => '.com.infoblox.perl_api.Infoblox.DHCP.insert_fixed_address',
                                    'add_using_template' => '.com.infoblox.perl_api.Infoblox.DHCP.insert_fixed_address_using_template',
                                    'get' => '.com.infoblox.perl_api.Infoblox.DHCP.get_fixed_address',
                                    'modify' => '.com.infoblox.perl_api.Infoblox.DHCP.modify_fixed_address'
                                  },
               'ipv4addr' => '111.111.111.111',
               'match_client' => 'MAC',
               'mac' => '00:11:00:11:00:11',
               'disable' => 'false',
               '__type' => '.com.infoblox.perl_api.Infoblox.DHCP.FixedAddr'
             }, 'Infoblox::DHCP::FixedAddr' )
    ];

But if I try and call a reference using '$_->mac' within the 'foreach (@searh)' loop, I get an error:

 "Can't call method "mac" on unblessed reference at ./connect_test.pl line nn."

My coding skills fail at this point, any info or direction would be much appreciated.

Linus Kleen · Accepted Answer · 2011-11-11 11:25:55Z

2

The first element in the array is the blessed reference.

$_->[0]->mac

You can directly access elements in array references with the -> operator (as above) or completely dereference them to a list: @list = @{$array_reference}.

answered Nov 11, 2011 at 11:25

Linus Kleen

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1 Comment

user1039417 Over a year ago

Thank you so much, simple when you know how.

Zaid · Accepted Answer · 2011-11-11 11:35:45Z

1

Each item stored in @search is an arrayref itself.

# If arrayref contains only one     | # If multiple objects expected
# Infoblox::DHCP::FixedAddr object  | # inside @search
                                    |
                                    |
foreach ( @search ) {               | foreach my $item ( @search ) {
                                    | 
    my $obj = shift @$_;            |     foreach my $obj ( @$item ) {
    my $mac = $obj->mac;            |
}                                   |         my $mac = $obj->mac;
                                    |     }
                                    | }

answered Nov 11, 2011 at 11:35

Zaid

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1 Comment

user1039417 Over a year ago

Thank you for the examples Zaid, that has cleared up a sizeable gap in my knowledge base.

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