Seamus

And wrt the Wikipedia article you referenced, there's this: "keepalives are an optional feature, and if included must default to off". Don't know about your systems of course, but in all of mine (except an old 2011 Macbook running High Sierra), pmset reports tcpkeepalive as 1 - which I guess is enabled. And there's no need continuing this - I simply asked if you could share your source for Apple's documentation on tcpkeepalive - you've not done that, so I'll assume that you - like me - are operating without it.

Thank you for the tutorial, but you are still missing the point: Apple has made choices regarding how TCP KeepAlives operate in various power conservation modes (e.g. "Power Nap", Sleep, Standby, etc), but they have not documented those choices. The label tcpkeepalive is not mentioned in man pmset. So - how do you know that it is working for all processes when in sleep mode?

tcpkeepalive is not addressed in man pmset - or anywhere else I can find. And so I wondered if you knew something

I wonder if you could share with us where you find Apple's documentation covering use of the tcpkeepalive option in pmset? It's not in man pmset AFAICT - at least not on Catalina or Mojave or High Sierra.

@Ghanima : Consistency is all I ask!

@MartinSleziak: Mmm... sounds terribly arcane... one of the reasons I don't use chat very often! :) And thanks for your help!

@MartinSleziak - no, I don't use the chat rooms often; I did not know that. It was a "public" room, so I assumed I could reach anyone.

@greenonline, @darthvader ... I've posted a Question for the moderators - please take a look at it when you can.

I have followed up twice with "Flags", requesting an explanation for the deletions, but AFAICT these requests have been ignored. So... I thought I'd try here in the "Chat Rooms" to see if I could raise a moderator, and get an answer to my question: "Why were my comments removed/deleted?"

I have a question for "the moderators": I made some comments to this question that were removed/deleted. I didn't delete them, and so I assume this must have been a moderator that did.

@Ghanima: I want you to run for moderator - assuming this is something you're willing to take on. Can I do anything to help?

Oops! That's temperament - not temprament

@Ghanima: Why don't you do it? You've got the experience certainly, and from the little bit I've observed you have the temprament for it also.

So is @goldilocks not going to run for another moderator term?

@nohillside: Due to Debian's alternatives system, I didn't think this would yield anything useful. But, FWIW type awk ==> awk is /usr/bin/awk both fm the CLI, and in the function.

@SmallClanger: Turns out that your suggestion works with awk/mawk :) Please write that up as an answer & I'll accept & upvote.

@meuh, et. al: You were on the right track; the issue seems to be that on my system (Raspberry Pi OS), awk is aliased to mawk. After installing gawk, and changing my function to use gawk instead of awk/mawk - it works as expected. Which - I guess - seems to change my question a bit... Suggestions?

@meuh: bash --version ==> GNU bash, version 5.2.15(1)-release (aarch64-unknown-linux-gnu). Pls see EDIT in Q for other info.

Oh - just one other minor thing... please delete any extraneous comments... too many are "frowned upon", and it limits others from commenting

You're welcome - have a good day.

Anyway - I've got some "chores" I need to tend to if you don't have any other questions?

And just for reference, you may want to connect your voltmeter across the resistor&LED. When running at 50% duty cycle (duty_cycle=100000) you should see about 1.6 - 1.7 volts

echo 25000 > duty_cycle

echo 175000 > duty_cycle

Yeah... I haven't had time to chase that pwm-2chan thing down yet Anyway - now you can play round & change the brightness of the LED

No... I think I mentioned using pwm2 - did I not?

You're welcome... what did we do differently here from what you did?

tell me what you see

echo 1 > enable

now... drum roll, please :)

OK, good enough

Now - 1 more echo command... after you enter it, you should see your LED illuminate immediately... Oh - forgot to ask what sive series resistor are you using?

Be sure you are in the folder /sys/class/pwm/pwmchip2/pwm2

? hmmm does your user have sudo privileges?

echo 100000 > duty_cycle

echo 200000 > period

OK, now enter the following two echo commands on separate lines:

you should get this:

OK - that's a good sign... now cd into the dir pwm2, and do another ls

Do you mean a new folder is added? Is it named pwm2??

??? what do you mean... what exactly comes up?

at the prompt

echo 2 > export

I mean:

echo 2 > export at the prompt

then, enter the following:

If you're not in that dir, use cd to move there

Check that you're in the proper directory: