Set Reaction > Script Action

[toggledbits]

I don't know what the first expression is/was, but the second one is correct and has parsed the value correctly. You can now refer to data in the object via ps4wakerparse.statusCode for example. For names that contain special characters, like host-id, you need to use the alternate (quoted identifier) syntax ps4wakerparse["host-id"]

[cw-kid]

@toggledbits

Seems to be working and pulling out the required data:

The first expression named "ps4wakercheck" is the inital output of the shell command "ps4-waker check".

[toggledbits]

OK. I see that it's not consistently clearing the error from some prior usage on ps4wakercheck, that's what's confusing/odd, so I've fixed that for today's build as well (PR 0000235).

[toggledbits]

By the way, it's much more efficient to use expressions in ps4powerstatus and ps4runningapp than it is to use Set Variable actions to set them. That's kind of doing it the hard way.

[cw-kid]

@toggledbits

For the value in the expression "ps4powerstatus" its either going to be:

200 = ON
620 = OFF

How can I have another expression that will translate those code numbers in to human text that I can then send to Vera / Home Remote ?

Thanks

[cw-kid]

@toggledbits said in Having issues with a shell command:

By the way, it's much more efficient to use expressions in ps4powerstatus and ps4runningapp

Understood I have changed it and removed the set variable actions:

EDIT:

Don't think it likes that, I get these error when I press the "Reset" button on the rule.

[toggledbits]

That's right.

Show all the values when you post an error, please.

[cw-kid]

This is what the summary card looks like after hitting the Reset button and then the red alerts come back each time after I have cleared them

Expressions:

Not sure why the alerts are appearing ?

[toggledbits]

No errors there.

[toggledbits]

Have you removed the Set Variable actions?

[cw-kid]

@toggledbits said in Having issues with a shell command:

Have you removed the Set Variable actions?

Yes

The bell icon goes red when the rule is Reset.

[toggledbits]

Removing the actions is/was correct. I'll give this a try later today and see

[cw-kid]

Using a Vera Multistring plugin device.

I added these in the rules Reaction to send the values to the generic sensor device in Vera etc.

Just need to translate codes 200 and 620 to "On" and "Off" instead.

I could maybe delete these two expressions from the rule also.

EDIT:

I've just seen a new field called "status" maybe I can use that instead.

On = "OK"

Off = "Standby"

[toggledbits]

I had a moment to do a quick test. Duh; I'm forgetting my own code's behavior. This is actually pretty simple. When you reset the rule, all state and expression/variable values are removed, so effectively, everything is null. When the rule is then re-evaluated, expressions are evaluated first, and since ps4wakercheck is null at that point because the action has not yet run, then ps4wakerparse is also null, so the last two expressions can't dereference through null and throw an evaluation error. This is actually all expected, correct behavior.

You can probably just clear these two spurious errors (caused by the reset/no data condition at rule "boot"), as they will not happen again, typically. The only other way you would see this is if the command actually fails hard in some way and produces no parseable JSON output. Then you'll get alerts again, but that's probably good because you might want to know that.

Another way to handle it is to simply modify the last two expressions like this:

• ps4powerstatus = ps4wakerparse?.statusCode
• ps4runningapp = ps4wakerparse?["running-app-name"]

The ?. and ?[ operators, described in the docs, are special coalescing versions of the standard . and [ operators that guard null on their left-hand operands. If the left-side operand value is null, the coalescing operator will simply return null and no error will be issued. I think this also makes sense in this application. These coalescing operators are provided for exactly this kind of case, so this is a perfect example of their use, and you should familiarize yourself with them (and apply them often).

[toggledbits]

You can map a value from one to another using a simple map object, like this:

mappedStatus = ( { '200': 'On', '620': 'Off' } )?[ ps4wakerparse.statusCode ] ?? "unknown"

Here, we create an object on the fly (the ( { ... } ) part), dereference through it using the ?[ coalesce operator, which will return null if the value of statusCode doesn't match anything in the object, and then use a final ?? coalesce operator to change an unmapped/null to the word unknown

Ref: Reactor docs: Expressions

[cw-kid]

@toggledbits said in Having issues with a shell command:

The ?. and ?[ operators

That fixes it the red alerts don't appear any more when Resetting the rule.

Thanks

[cw-kid]

@toggledbits

Finished device in Vera:

Home Remote dashboard tile:

Had to just add an additional ? to this code to stop the red alert appearing again.

( { '200': 'On', '620': 'Off' } )?[ ps4wakerparse?.statusCode ] ?? "unknown"

And now the alert doesn't come back again when resetting the rule.

So I think everything is all working fine now, at least while the PS4 is turned ON.

Thanks

[cw-kid]

@toggledbits

So everything last night was working OK when the PS4 was turned ON.

I am now testing when the PS4 is OFF.

Some issues the shell command doesn't seem to be populating the ps4wakercheck variable for some reason and its null.

Vera device when PS4 is OFF

If I run the "ps4-waker check" command in terminal it outputs correctly as expected.

root@HP-Thin01:/home/stuart# ps4-waker check
{
  "type": "device",
  "statusLine": "620 Server Standby",
  "statusCode": "620",
  "status": "Standby",
  "host-id": "C863F1400EF1",
  "host-type": "PS4",
  "host-name": "PS4-806",
  "host-request-port": "997",
  "device-discovery-protocol-version": "00020020",
  "system-version": "08520011",
  "address": "192.168.0.201"
}

Log file:

2021-08-02T10:51:27.077Z <Engine:NOTICE> Starting reaction PS4 Waker Check<SET> (rule-krq612qx:S)
2021-08-02T10:51:27.077Z <Engine:5:Engine.js:1378> Engine#1 reaction rule-krq612qx:S step 1 shell command { "command": "ps4-waker check", "rule": "rule-krq612qx", "rvar": "ps4wakercheck", "ignore_exit": true }
2021-08-02T10:51:27.094Z <Engine:5:Engine.js:1105> _process_reaction_queue() task returned, new status 3; task 19
2021-08-02T10:51:27.098Z <Engine:5:Engine.js:1140> _process_reaction_queue ending with 1 in queue; none delayed/ready; waiting
2021-08-02T10:51:27.617Z <Engine:ERR> Engine#1 reaction PS4 Waker Check<SET> step 1 error executing shell `ps4-waker check': Error: Command failed: ps4-waker check

2021-08-02T10:51:27.620Z <Rule:5:Rule.js:674> Rule#rule-krq612qx rule set variable ps4wakercheck = (object) (null)
2021-08-02T10:51:27.621Z <Engine:5:Engine.js:940> Engine#1 set variable rule rule-krq612qx ps4wakercheck=(null), requesting re-eval
2021-08-02T10:51:27.624Z <Rule:5:Rule.js:962> Rule#rule-krq612qx (PS4 Waker Check) evaluate() acquiring mutex
2021-08-02T10:51:27.625Z <Engine:5:Engine.js:1140> _process_reaction_queue() wake-up!
2021-08-02T10:51:27.625Z <Rule:5:Rule.js:966> Rule#rule-krq612qx._evaluate() mutex acquired, evaluating
2021-08-02T10:51:27.626Z <Rule:5:Rule.js:970> Rule#rule-krq612qx update rate is 2/min limit 60/min
2021-08-02T10:51:27.627Z <Rule:5:Rule.js:892> Rule#rule-krq612qx evaluateExpressions() with 3 expressions
2021-08-02T10:51:27.628Z <Rule:5:Rule.js:982> Rule#rule-krq612qx._evaluate() trigger state now false (was false)
2021-08-02T10:51:27.629Z <Rule:5:Rule.js:984> Rule#rule-krq612qx._evaluate() constraints state true
2021-08-02T10:51:27.629Z <Rule:5:Rule.js:993> Rule#rule-krq612qx rule state now false, changed no
2021-08-02T10:51:27.631Z <Engine:5:Engine.js:1101> _process_reaction_queue() running task 19 { "tid": 19, "id": "rule-krq612qx:S", "rule": "rule-krq612qx", "__reaction": [RuleReaction#rule-krq612qx:S], "next_step": 2, "status": 1, "ts": 1627901487069, "parent": --null--, "__resolve": --function--, "__reject": --function--, "__promise": [object Promise], "attempts": 1 }
2021-08-02T10:51:27.632Z <Engine:NOTICE> Resuming reaction PS4 Waker Check<SET> (rule-krq612qx:S) from step 2
2021-08-02T10:51:27.632Z <Engine:NOTICE> PS4 Waker Check<SET> delaying until 1627901492632<02/08/2021, 11:51:32>
2021-08-02T10:51:27.633Z <Engine:5:Engine.js:1105> _process_reaction_queue() task returned, new status 2; task 19
2021-08-02T10:51:27.636Z <Engine:5:Engine.js:1140> _process_reaction_queue() ending with 1 in queue; waiting for 1 (next delayed task)

If I turn ON the PS4 it starts working again and the variable is populated with data via the shell command.

[toggledbits]

Make sure you restarted Reactor after installing the update. The ignore flag is in the action data (so the UI has done the right thing), but the log file content looks like an older version of the Engine running.

[toggledbits]

Any update on this?