How to process variables into exec-node running a C-program

General
1

I hope I didn't miss any post or information which would resolve my issue, but I seem to be unable to find anything.
I'm quite new to Node-Red and Node.Js in general, just been able to run a few other things yet, which have been a lot easier to manage.

I want to run a C executable via the exec-node, input variables and get different variables back.
The program is basically a script deciding the appropriate output in regards to the input. These variables change each time the exec-node is run in a set interval.

My problem right now is the communication between the C-Code and Node-Red. I have compiled a basic "addOne"-program.
An Input Variable in Node-Red should be set to whatever number I want, the program adds 1 and outputs the result. For later implementation it is not necessary that the output is a different variable but it would be helpful.

I'm unable to set the variable in Node-Red or get the program to use any set variable and am a bit lost on what to search for after having found nothing that resolved my issue.

If I missed anything please let me know.

2

Does your C program accept/process command line arguments?

3

Not right now, but I would like to change that in the future.
Is the solution without command line arguments more complex?

4

It's easy(ish) to put the program pathname in the exec node and use msg.payload for command line argument[s] Of course each command line argument will be seen as a string.

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It gets more difficult if you are passing JSON or some special characters which have to be protected from being mangled by the shell.

5

Have you ever tyied Native Abstraction for Node.js
A math demo is here NAN

6

I have worked out the command line argument functionality in the meantime.
You were right, it made the input much easier, although I still have to test how easy that will be when working with 3-digit large arrays later on.

Thanks!

7

I have not heard of that yet.
Will look up what that is capable of.

8

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