Re: [GLLUG] How can I find out if external audio is connected?
On Mon, 26 Sep 2022, Dr. Axel Stammler via GLLUG wrote: I would like to remind myself of external amplifiers uselessly running so I would like to play a short sound signal once in a while if there is no audio playing. OTOH, the signal should obviously not be played over the built-in speakers. So, how can I find out (preferably using a command-line utility in a script) which of the ‘audio out’ connectors are actually connected to anything (or just have a plug in them) and if anything is played over these connections? I'm not sure if it's possible to programmatically determine external vs built in, but if you're not opposed to simply hard wiring this in a cron job you set up yourself, then you can just look up up the devices with `pactl info` you'll need to has this through some perl or something and then grep out the local device leaving you with the various attached external audio devices before using something like aplay just send audio. This assumes ALSA and pulseaudio which is reasonably likely but audio in Linux changed over many years so you might have Oss or you might be using pipewire etc etc. Determining if audio is currently playing will also be interesting as these new technologies simply attempt to mix audio together rather than block when you're device is in use. You might be able to kludge up some sort of grep against a console based volume bar indicator. This sounds like a fun little project to attempt using a bunch of Unix command line tools :) - Damion-- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
Re: [GLLUG] ssh local port forwarding remote interface binding.
On Thu, 14 Jan 2021, Tim Woodall via GLLUG wrote: On Thu, 14 Jan 2021, damion.ya...@gmail.com wrote: On Thu, 14 Jan 2021, Tim Woodall via GLLUG wrote: In ssh -N -L 8080:webserver:80 gateway Is there any way to specify which interface should be bound on gateway other than by changing the routing table on gateway? I found https://unix.stackexchange.com/questions/16057/use-ssh-with-a-specific-network-interface And my ssh manpage has indeed got a -b to change the bind address on your initial outgoing connection and also -B to change bind interface. The rest about binding for the listening onb a fwd is indeed not helping your cause. I'll give it a try but I assumed that was controlling the interface used on the local machine, i.e. the connection to gateway rather than the one from it. Yes moments after sending I re-read your email and realised what you wanted was the sshd to be behaving differently, if you missed it this is the content: --- content from followup email --- Ah I misunderstood. You want the machine called "gateway" to bind against a specific interface for its outgoing connectons, when doing the forwarding. I had assumed this to be done by your choice of IP in the portion before the first port the "webserver" being remote and the part you want to route out to but I think I can see the issue now. How do make sshd choose to use a particular binding for a host. I can't see a -b in man sshd but man sshd_config does have GatewayPorts. Otherwise route update or socat sound reasonable. - Damion -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
Re: [GLLUG] ssh local port forwarding remote interface binding.
On Thu, 14 Jan 2021, damion.ya...@gmail.com wrote: On Thu, 14 Jan 2021, Tim Woodall via GLLUG wrote: In ssh -N -L 8080:webserver:80 gateway Is there any way to specify which interface should be bound on gateway other than by changing the routing table on gateway? I found https://unix.stackexchange.com/questions/16057/use-ssh-with-a-specific-network-interface And my ssh manpage has indeed got a -b to change the bind address on your initial outgoing connection and also -B to change bind interface. The rest about binding for the listening onb a fwd is indeed not helping your cause. Ah I misunderstood. You want the machine called "gateway" to bind against a specific interface when doing the forwarding. I had assumed this to be done by your choice of IP in the portion before the first port the "webserver" being remote and the part you want to route out to but I think I can see the issue now. How do make sshd choose to use a particular binding for a host. I can't see a -b in man sshd but man sshd_config does have GatewayPorts. Otherwise route update or socat sound reasonable. - Damion - Damion -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
Re: [GLLUG] ssh local port forwarding remote interface binding.
On Thu, 14 Jan 2021, Tim Woodall via GLLUG wrote: In ssh -N -L 8080:webserver:80 gateway Is there any way to specify which interface should be bound on gateway other than by changing the routing table on gateway? I found https://unix.stackexchange.com/questions/16057/use-ssh-with-a-specific-network-interface And my ssh manpage has indeed got a -b to change the bind address on your initial outgoing connection and also -B to change bind interface. The rest about binding for the listening onb a fwd is indeed not helping your cause. - Damion -- GLLUG mailing list GLLUG@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/gllug
