You can serailize any(*) datastructure using Storable (Standard). Have a look into the manpage.

*: any common structure

There are plenty of modules that do the job, with FreezeThaw and Storable being the most popular choices (it seems...).

If, for any reason, you need an handcrafted solution, it depends on the data you have. Long time ago I used to serialize hashes using \cF (control-F) as field separator (i.e.: key/value separator) and \cR as record separator (i.e.: separator between key/value couples).

Obviously, this will break if you have binary data.

Ciao!
--bronto

# Another Perl edition of a song:
# The End, by The Beatles
END {
  $you->take($love) eq $you->make($love) ;
}

You can use Storable

use Storable qw(nfreeze thaw);
$scalar = nfreeze(\%hash);
%hash_copy = %{ thaw($scalar) };
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If you need to have hash with keys - usenames and values as data structure (not scalar) you can use tie... for binding to sql database use eg. Tie::RDBM module. Example from docs:

use Tie::RDBM;
tie %h,Tie::RDBM,'mysql:test',{table=>'Demo',create=>1,autocommit=>0};
$h{'key1'} = 'Some data here';
$h{'key2'} = 42;
$h{'key3'} = { complex=>['data','structure','here'],works=>'true' };
$h{'key4'} = new Foobar('Objects work too');
print $h{'key3'}->{complex}->[0];
tied(%h)->commit;
untie %h;
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The idea is to have a hash table for a number of users, so I need to be able to convert a hash to a scalar and vice versa.

Do you actually need to convert to a scalar? Could references solve your problem (ie: an array of hashes or a hash of hashes)? Check out perlreftut if you're not familiar with references. Ignore me if you are :-)