Perl in a Nutshell, 2nd Edition

Storable

Storable.pm allows you to keep peristent state on your Perl data structures, which include objects of type SCALAR, ARRAY, HASH, and REF. In other words, Storable lets you deal with any Perl types that can be conveniently stored on disk and retrieved at a later time. At the heart of Storable is store, which takes a reference to the object that will be stored and the filename where the information should be written. And, while you’re statefully keeping your Perl data on a filesystem, retrieve will open the file where the data is kept so you can work with it. As of Perl 5.8, Storable is shipped with the source kit.

For the cost of a slight header overhead, you can store to an already opened file descriptor using the store_fd routine and retrieve from a file via fd_retrieve. These names aren’t imported by default, so you will have to do this explicitly if you need these routines. The file descriptor you supply must be opened for read if you’re going to retrieve and for write if you wish to store. For example:

#!/usr/local/bin/perl -w
use Storable;

my $state_file = '/tmp/emp.cache';
my %empdata = (EmployeeNumber => 1, Person => 'Nathan Patwardhan');
 
store(\%empdata, $state_file);
my $h_ref = retrieve($state_file);

Storable implements the following methods.