juo has asked for the wisdom of the Perl Monks concerning the following question:

Does anybody know of a module that can read a dumped file and put it back into a hash structure. Below you can see an example of the code to generate a dumped file of a hash table. But I could not find a module to read the dumped file and put it back into a hash table. 


open (STDOUT, ">whatever.dat");
use Dumpvalue;
my $dumper = new Dumpvalue;
$dumper->dumpValue(\%flexlm);

[download]

Result of the dumped file 

'dataParams' => HASH(0x1ee5ef4)
   'license_feature' => HASH(0x1ee5f0c)
      'val' => 'geditor'
   'license_server' => HASH(0x1ee5f30)
      'val' => '10.210.134.126'
   'licenses_used' => HASH(0x1ee5f78)
      'val' => 7
   'machine_names' => HASH(0x1ee5fcc)
      'parmOptions' => ARRAY(0x1cd9b24)
         0  'solw0328'
         1  'solw0082'
         2  'vasw1006'
         3  'lav000021453a'
         4  'tczw5216'
         5  'CRKW388'
         6  'vasw1005'
   'total_licenses' => HASH(0x1ee5f54)
      'val' => 15
   'user_names' => HASH(0x1ee5fa8)
      'parmOptions' => ARRAY(0x1b8442c)
         0  'solwebef'
         1  'solwebef'
         2  'vaskhall'
         3  'lvlvalor'
         4  'tczrale'
         5  'crkjcree'
         6  'vasplund'

[download]

Replies are listed 'Best First'.
Re: Module to read a dumped file
by ropey (Hermit) on Feb 11, 2003 at 14:42 UTC
    Looks like your code doesn't dump your data structure correctly. ('machine_names' => HASH(0x1ee5fcc)) will not work. Have a look at Data::Dumper, that should provide all the functionality you need.
[reply]

      I have checked out the Data::Dumper and indeed it allows to dump a hash table and it is slightly in a different structure then the dumpvalue does but I could not find how to read back a dumped file. Like dumpvalue it only goes in one direction. 

      use Data::Dumper;
open (STDOUT, ">whatever.dat");
print Dumper(%flexlm);
close STDOUT;

      [download]
      $VAR1 = 'dataParams';
$VAR2 = {
          'license_feature' => {
                                 'val' => 'geditor'
                               },
          'total_licenses' => {
                                'val' => '15'
                              },
          'machine_names' => {
                               'parmOptions' => [
                                                  'solw0328',
                                                  'solw0082',
                                                  'vasw1006',
                                                  'lav000021453a',
                                                  'tczw5216',
                                                  'CRKW388',
                                                  'vasw1005'
                                                ]
                             },
          'user_names' => {
                            'parmOptions' => [
                                               'solwebef',
                                               'solwebef',
                                               'vaskhall',
                                               'lvlvalor',
                                               'tczrale',
                                               'crkjcree',
                                               'vasplund'
                                             ]
                          },
          'licenses_used' => {
                               'val' => 7
                             },
          'license_server' => {
                                'val' => '10.210.134.126'
                              }
        };

      [download]
[reply]
[d/l]
[select]
        I could not find how to read back a dumped file
        Like so 
        use Data::Dumper;

my %hash = qw( foo one bar two baz three );

open  DATA, ">whatever.dat";
print DATA Dumper(\%hash);
close DATA;

my %hash2 = %{ do "whatever.dat" };
print Dumper(\%hash2);

__output__

$VAR1 = {
          'foo' => 'one',
          'baz' => 'three',
          'bar' => 'two'
        };

        [download]
        For more info see the ever-magical do() function.
        HTH

        _________
        broquaint

[reply]
[d/l]
        Once you have read it in from the file and stored in a scalar, just do 
        
my $ref = eval $data;

        [download]
[reply]
[d/l]
Re: Module to read a dumped file
by CountZero (Bishop) on Feb 11, 2003 at 15:19 UTC

    I always understood that you could eval the output of Data::Dumper to get the original variable structure back.

    Reading the outputfile into a scalar variable and eval-ing this scalar should to the trick.

    CountZero

    "If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law

[reply]
Re: Module to read a dumped file
by Jeppe (Monk) on Feb 11, 2003 at 16:57 UTC
    If you don't need to transfer the data between platforms, Storable is up to the job. 
    $string = freeze($hashref);
$hashref = thaw($string);

    [download]
    Also, Data::DumpXML is worth looking into. And the good old Data::Dumper.
[reply]
[d/l]
Re: Module to read a dumped file
by jammin (Novice) on Feb 11, 2003 at 17:32 UTC
    To read a Data::Dumped file back I just use: my $hash = do 'filename';
[reply]
Re: Module to read a dumped file
by thor (Priest) on Feb 12, 2003 at 00:33 UTC
    if it's persistence you're looking for and don't care if it's readable or not, have a look at Storable

    thor

[reply]

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