Non-GUI, single processort inter process massaging - how?

[Chris Green]

I have a need to allow short-lived 'client' processes to interrogate a
single long-lived 'server' process on a small system (specifically a
BeagleBone Black).

The server process reads values from external hardware and this
needs to be done by a single process to ensure that it works as
intended and to allow simple smoothing algorithms to be applied.
Using multiple processes to do this would be difficult.

I want to be able to interrogate the server process from several
client processes, some will interrogate it multiple times, others once
only.  They are mostly (all?) run from the command line (bash).

There is no GUI and all these processes will always be on a single
system.  

A single multi-threaded process doesn't really work because I don't
see how one could then run something at command line which could get
values from the server process.

So - what's the best approach to this?  I've done some searching and
most/many of the solutions seem rather heavyweight for my needs. Am I
overlooking something obvious or should I try rethinking the original
requirement and look for another approach?


(currently each 'client' simply reads the hardware directly using a
Python module I have written, however this hits the hardware more than
necessary and makes smoothing and such difficul)

-- 
Chris Green
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