mpc idle message purpose/utility?

[iconoclasthero]

Is this a functional option?

mpc docs point back to the list of idle options in the protocol docs which includes message:

message: a message was received on a channel this client is subscribed to; this event is only emitted when the client’s message queue is empty

But since mpc subscribe channel is a blocking listener on channel, the "subscription" is basically just an open blocking FIFO listener and thus the client is only "subscribed" to the channel while it's open/blocking—until SIGINT is received. When that's closed then it is no longer "subscribed."

mpc -q idle message channel does not subscribe to channel and idle until an event breaks the idle—i.e., a message is received on channel—it errors:
Unrecognized idle event: channel

So is there some combination of mpc idle message with or without mpc subscribe channel that has a functional idle utility or will mpc idle message will just idle indefinitely?

[subtlecaffeine]

It took me a while to try and figure this out and I have to admit...I'm still confused. So I think I need to ask the dreaded question:

What are you trying to accomplish?

The mpc message channel is for inter-client communication; it was not designed to be used directly by mpc. You would need to subscribe to a channel then idle on that channel...which you can't really do.

The feature was more designed for persistent clients...and literally for inter-client communication. It's probably in mpc just for completeness of the protocol.

If you want something event driven; then the best way is to talk to pretend you're a client and talk to mpd directly.

[iconoclasthero]

What are you trying to accomplish?

In short, I was looking for a way to break an mpc idle by sending a message and this seemed like a reasonable way to do it until I dug into it. I thought maybe I was missing something but clearly not.

At the end of the day, I'd pushed a bash script as far as I reasonably could and decided [read: capitulated to the fact] that in order to have a more robust daemon that could control mpd playback in the mode I wanted (i.e., "rock block" mode: intermittent random after n songs) I would need to use a programming language.

So now I have https://github.com/iconoclasthero/mpdgolinger which (by default) plays what classic rock DJs used to call a "4-pack" "rock block" back when I used to listen to the radio. This lets me listen to a few songs in a row by what is most likely from the same artist/album before moving to another. Right now, it's a 4-pack of Stevie Ray Vaughn...

[borine]

Is this a functional option?

mpc idle message is an option that has no useful function that I can imagine. It does exactly as you have described.

If you just want to monitor a channel and simply receive notification of messages posted to that channel then use mpc subscribe channel.

If you want to both monitor a channel and receive notification of other event types then mpc cannot do that; so you will have to find, or create, some other client.

[iconoclasthero]

Answer: none.