We're in the process of migrating between two different reporting systems at work, and part of this will involve converting client identifiers from 4-character strings to 7-character ones.

We're migrating incrementally, for various reasons (the systems are mission-critical, most importantly), and hence it's important that scripts and systems that already exist can interface, short-term, with the new code and systems put in.

To cope with the new client identifiers, I've created a hash that contains data for each client keyed on the new, 7-character, identifier, which was simple enough to do.

What I now need to do is find a way of having the old-style identifiers reference the new ones, so a call to, for example, $clients{ABCD} actually uses (and potentially modifies) the data in $clients{ABCDEFG}, rather than having to store the data twice and subsequently modify the data twice.

I've tried to do this using references, with the code below: 

my %new_client_hash;
foreach my $old_key (keys %clients) {

   my $new_key = $clients{$old_key}{new_sys_id};
   delete $clients{$old_key}{new_sys_id};

   $new_client_hash{$new_key} = $clients{$old_key};
   $new_client_hash{$old_key} = \$new_client_hash{$new_key};
}

[download]
but this doesn't work - some of the new keys are "displaced" by the old keys, and some of the keys are simply left referencing an empty hash.

Does anyone know of a way to achieve this, or am I missing something obvious in the code there?

Any help would be appreciated.

Thanks,
-- Foxcub

In reply to Multiple keys describing a single hash element by Tanalis

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