Dear Monks

I tried to write a package which is used like 
my $h2f = new MyPackage() ;
$h2f->{fsize} = 1000 ;
print "filename = " . $h2f->{fname} ;
$h2f->cleanup() ;
....

[download]
What this package must do is
1) store / retrieve key-values from a file
2) modify (if necessary ) values STOREd or FETCHed

Here is my code so far 
#! /usr/bin/perl -l

use strict ;
use warnings ;
use Data::Dumper;

package NewStdHash;

use Tie::Hash;
use Fcntl qw(:DEFAULT :flock) ;   # For O_RDWR, O_CREAT, etc.
use NDBM_File ;

our @ISA = qw(Tie::StdHash);

$| = 1 ;

sub new {
  my $class = shift ;
  my $self = bless {}, ref $class || $class ;
  return $self->_init( @_ ) ;
}

sub _init {
  my $self = shift ;

  tie %$self, 'NewStdHash' ;

  my %storage = () ;
  tie %storage, 'NDBM_File', "demodata",O_RDWR|O_CREAT,0777 or die "$!
+";
  $self->{storage} = \%storage ;

  return $self ;
}

sub cleanup {}

sub FETCH {
  my ( $self, $key ) = @_ ;
  # do some stuff
  return $self->{storage}->{$key} ;    
}

sub STORE {
  my ( $self, $key, $value ) = @_ ;
  # do some stuff
  $self->{storage}->{$key} = $value ;  
}

sub DESTROY {
  my $self = shift ;
  print "DESTORY" ;
  untie($self->{storage}) ;
  untie($self) ;
}

package main ;

my $mh = new NewStdHash() ;
print "val is " . $mh->{abc} ;
$mh->{abc} = 20 ;

[download]
Unfortunately, it doesn't store or retrieve anything from the file. The only solution so far was to store the NDBM_File TIEd hash in a global variable, but I prefer storing it in $self!
Is it the TIEd hash inside a TIEd hash that causes the problem or something else. Any suggestions ?

cheers

In reply to TIEd object (TIEd hash inside a TIEd hash) by jeanluca

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.