It cannot be done.

The same hash key cannot contain

both a numeric value:    ...{'SerialNumberUserAttribute'} = 12345;

and a subtree of hashes: ...{'SerialNumberUserAttribute'}{'LanMan'}{'Value'}="";

BrowserUk correctly identified that your proposed structure is flawed. But beyond that, certainly someone has done this (the right way) before... enough times that there would be a module on CPAN for it: Win32::TieRegistry. It's not quite the direction you were headed, but it's a reasonably well tested solution.

$hash{'HKEY_LOCAL_MACHINE'}{'SOFTWARE'}{'Vendor'}{'Product'}{'CurrentV
+ersion'}{'
+Tokens'}{'Encotone'}{'SerialNumberUserAttribute'}=12345;
$hash{'HKEY_LOCAL_MACHINE'}{'SOFTWARE'}{'Vendor'}{'Product'}{'CurrentV
+ersion'}{'
+Tokens'}{'Encotone'}{'SerialNumberUserAttribute'}{'LanMan'}{'Value'}=
+"";
[download]

a hash-entry can't be 12345 and a hash-ref to {'LanMan'}... at the same time.

consider ... {value}=12345

> Anybody have any ideas?

first step should be to build the mainpath as string with splits and joins.

then eval this string to autovivify this hash, and assign a ref to a $subhash to it.

This $subhash -ref can be populated now with all entries which come.

UPDATE

if you don't like evals build the HoH-path in a loop (line 163)

  DB<160> $line='HKEY_LOCAL_MACHINE\SOFTWARE\Vendor\Product\CurrentVer
+sion\Tokens\Encotone\SerialNumberUserAttribute=12345'

  DB<161> ($path,$value)= split /=/, $line

  DB<162> $subhash=$hash={}

  DB<163> $subhash = $subhash->{$_} = {} for split /\\/,$path

  DB<165> $subhash->{value}=$value

  DB<166> $subhash->{LanMan}{value}=""

  DB<167> $subhash->{LanMan}{type}="REG_SZ"

#... and so on for all sub-entries ...

  DB<168>  $hash
 => {
  HKEY_LOCAL_MACHINE => {
        SOFTWARE => {
              Vendor => {
                    Product => {
                          CurrentVersion => {
                                Tokens => {
                                      Encotone => {
                                            "SerialNumberUserAttribute
+" => { LanMan => { type => "REG_SZ", value => "" }, value => 12345 },
                                          },
                                    },
                              },
                        },
                  },
            },
      },
}
[download]

now repeat these steps for all paths!

HTH

UPDATE

this might delete older sub-structures from previous paths

DB<163> $subhash = $subhash->{$_} = {} for split /\\/,$path

so better do

$subhash = $subhash->{$_} //= {} for split /\\/,$path

Thanks for the reponses, I realize now that my manual example is flawed...

> I realize now that my manual example is flawed...

Line 165 in my code solved this. You need a dedicated key in a subhash for "direct" values and your fine.

It's disputable if "value" is a good choice for a key-name, but that's up to you.

Cheers Rolf

This is a case where autovivification and hashrefs are your friends. With a helping hand from some creative data structure manipulation.

You have two issues:

1. how to create a hash of hashes without knowing the depth of the structure in advance.
2. How to include a value for the entire dimension three levels from the bottom, knowing, as others have pointed out, that an element cannot contain at once a value and a reference to the lower levels of the structure.

#!/usr/local/bin/perl
use strict;
use warnings;

use Data::Dumper;
$Data::Dumper::Sortkeys = 1;

print "Content-type:text/html\n\n";

my $line1 = 'HKEY_LOCAL_MACHINE\SOFTWARE\Vendor\Product\CurrentVersion
+\Tokens\Encotone\SerialNumberUserAttribute=12345';
my $line2 = 'LanMan:= ; REG_SZ';

my @line1_parts = split(/[=\\]/, $line1);
my @line2_parts = split(/:= ;/, $line2);

my %hash;
my $href = {}; 
my $i;
for $i (0 .. $#line1_parts) {
    if ($i == 0) {
        # for the first time around, create the first level of the str
+ucture, itself as a hash.  Autovivification means that simply referri
+ng to it creates it.  No need to put anything in it yet.
        $hash{$line1_parts[$i]} = {};
        #create a hash reference to that element (which is itself a ha
+sh);
        $href = \%{ $hash{$line1_parts[$i]} };
    }
    elsif ($i == $#line1_parts) {
        # last time around, create the acutal hash elements you want, 
+filling in down to the bottom level with dummy elements for the Seria
+lNumberUserAttribute.
        $href->{'dummy'} = $line1_parts[$i];
        $href->{$line2_parts[0]}{'Value'}="";
        $href->{$line2_parts[0]}{'Type'}=$line2_parts[1];
    }
    else {
        # each next time around, create the next level of the structur
+e, itself as a hash, tacked onto the hash that the hash ref points to
        $href->{ $line1_parts[$i] } = {}; 
        # move the hash ref to this new hash
        $href = \%{ $href->{$line1_parts[$i]} };
    }
}

print "<pre>\n";
print Dumper(\%hash);
print "</pre>\n";
[download]

$VAR1 = {
 'HKEY_LOCAL_MACHINE' => {
   'SOFTWARE' => {
     'Vendor' => {
       'Product' => {
         'CurrentVersion' => {
           'Tokens' => {
             'Encotone' => {
               'SerialNumberUserAttribute' => {
                 'LanMan' => {
                   'Type' => ' REG_SZ',
                   'Value' => ''
                 },
                 'dummy' => '12345'
               }
            }
          }
        }
      }
    }
  }
}
[download]