[Info-vax] Long uptime cut short by Hurricane Sandy

[Stephen Hoffman]

On 2013-02-05 02:17:28 +0000, AEF said:

> On Feb 3, 3:31 pm, Stephen Hoffman <seaoh... at hoffmanlabs.invalid>
> wrote:
>> 
>> Environment variables aren't a direct match to logical names.
>> Similarities, yes, but there also are substantive differences, too.
> 
> Close enough for this. I just need to be able to use the variable as
> part of a path.
> 
> Seems to me that at the most basic level, logical names are
> environment variables, in a sense anyway. Now, they have a much richer
> structure, with the different tables of varying scope, the various
> access modes, search lists, and what not. Their chief use is in
> device- and file-specs, of course. But they're also used in MAIL, for
> queues, for storing data, and more. So it's just a matter of what's
> translating them in what context. There's the automatic translation
> when part of a generalized file-spec, and automatic translation in
> certain other contexts. That's all different from environment
> variables in Unix. But I don't need all that for this. I just need the
> ability to have something I can use in a path.

So you are seeking a key-value data store, something that logical names 
classically excel at stinking at.

Logical names got us the morass that is the DEC C feature logical 
names, after all.

Sure, it works.

At least until you trip into some other user; a collision.

Or you need to scan all keys, as both VMS and environment variables 
lack wildcards.

Upgrades can be fun, where these are added or removed; there's no 
"attachment" back to the application.

No namespaces, for that matter.

There are other issues.

Environment variables aren't all that good at this, either.

Some systems use plists here, some use rc or config files, others more 
directly use K-V data stores, and there are a number of those.

A K-V data store also means you have the app and (maybe) the data file 
to tow around, and nothing else, too.  No particular set-up, and you 
don't need to get your environment variables loaded into the process.  
Stick the tool in your path, and stick the database... somewhere... and 
you're good to go.



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