[Reactor] Assignment to alarm ignored -- expression-driven global cannot be set by assignment

[toggledbits]

Sorry, but let's stick with one issue at a time, please.

I want to see if that Expressions page view is actually broken and not showing complete/valid data. Make a dummy rule that contains a variable expression condition using the free memory value, and show what that displays for "current value" in both the rule editor and in the rule status view.

[cw-kid]

It says null

[toggledbits]

Can you make sure RouterMemoryResponse is defined before the other two variables in the list, restart MSR and check again.

[cw-kid]

I can yes, however before I deleted them all and recreated them, the "RouterMemoryRaw" was above the other two in the list.

[cw-kid]

OK done - I also restarted MSR and did a hard refresh.

[toggledbits]

And the rule?

[cw-kid]

It still says "null"

[toggledbits]

OK. In RouterMemoryFree expression remove all of the (\\d+) strings so that the middle/second argument to match() is just "Mem:" by itself (no spaces or other data). Restart and hard refresh. Then re-check.

[cw-kid]

Like this ?

match( RouterMemoryResponse, "Mem:")

[toggledbits]

Yes, that's fine.

[cw-kid]

It now says -

Last value: (string) "Mem:"

And the test rule trigger -

[toggledbits]

OK. So your pattern isn't matching, it seems is actually the problem. You may have some special characters or strange spacing in your pattern that I cannot see in the screen shots. There could also be a tab or other non-space character that looks like a space coming back in the shell command output.

Try using this expression for RouterMemoryFree:

match( RouterMemoryResponse, "Mem: (\\d+) (\\d+) (\\d+)", 3 )

[cw-kid]

It appeared to evaluate as it flashed green, Value is null however.

This is what is in the "RouterMemoryResponse"

Last value: (string) " total used free shared buffers cached\nMem: 426020 330068 95952 3488 0 37716\n-/+ buffers/cache: 292352 133668\nSwap: 0 0 0\n"

[toggledbits]

OK. Try changing all of the spaces to \\s* like this:

match( RouterMemoryResponse, "Mem:\\s*(\\d+)\\s*(\\d+)\\s*(\\d+)", 3 )

[cw-kid]

@toggledbits That seems to work.

[toggledbits]

OK. So your router must be returning some space-looking character that isn't space in the string somewhere. That's fine... the \\s means match anything that looks like a space. That's your path forward.

[cw-kid]

Great thanks. I just need to know how to use a Global Expression in my rule now?

As using a value like ${{ RouterMemoryFree }} only seems to work if the expression is a local expression within the rule.

[cw-kid]

The Global Expressions look like this now. I have the used and free memory values OK.

[cw-kid]

Seems I can just do them as Local Expressions after all instead of Global ones.

[toggledbits]

If you are only going to push them out in the same Reaction to other places, that's fine. You don't be able to use them in conditions, though.