[PD] Linux: changing sound card params from patch, sending OS commands

[John Harrison]

Okay this solution of [receive pd] and [print] works great! Yes the 
resulting patch leaves the dialog box open but, oh well. Nobody is going 
to see the laptop screen anyway. Cron I guess isn't going to work 
because I don't know beforehand the specified times I want shutdown to 
occur. In terms of [shell] I could be reckless and run from root. This 
is a dedicated machine so should be OK..

Thanks so much!

-John

Claude Heiland-Allen wrote:

> John Harrison wrote:
>
>> I'm using Pd as part of the engine for an interactive art project. 
>> The setup is an old PII laptop running xubuntu Dapper. I'm stuck on a 
>> few things:
>>
>>    1. It's a long story but the bottom line is that it appears that I
>>       have to use this crappy computer as well as its less-than-steller
>>       internal sound card, and that the internal sound card or driver
>>       has some sort of bug which requires me to switch to ALSA *after*
>>       starting Pd. Everything else produces no sound. And OSS is
>>       completely inoperative. So is there a way I can do this in a
>>       patch? (The sound card is a Yamaha OPL3-SA23 BTW.)
>
>
> Create a little patch like:
>
> [receive pd]
>  |
> [print]
>
> Then use Pd's audio dialogue to set the audio up the way you want it, 
> which should print a long cryptic message.  Then recreate this message 
> in Pd, like this:
>
> [loadbang]
>  |
> "message that was printed with audio settings"
>  |
> [send pd]
>
> Alternatively you can send this audio settings message from the 
> command line that starts Pd, with the -send command line option.  
> Something like  'pd -send "; pd dsp 1"' works for activating DSP, the 
> same technique works for audio settings.
>
> However:  this has the side-effect of opening the audio settings 
> dialogue window, and I don't know how to close this window 
> programmatically
>
> This is the only way I have managed to get pd-0.39.2 to start with 
> JACK ports enabled, without having to manually activate them in the 
> dialogue window.  Needless to say it is very inconvenient, and it 
> would be much better if Pd really did obey the command line parameters 
> for audio settings.
>
>>    2. I'd like Pd to be able to send commands to the OS such as shutdown
>>       -h "now" when the gallery closes each evening. Is there a way to
>>       send such commands from a patch? The only thing I could think to
>>       do is send a message to a Python script using sockets....seems
>>       rather clumsy.
>
>
> There is the [shell] Pd external, but I've never used it myself.  I'm 
> thinking there would be permissions issues, depending if the user 
> running Pd has the right to shutdown the computer or not (I'm not 
> familiar with Ubuntu).  If the user running Pd doesn't have that 
> permission, I think socket communication is a logical way to send 
> information to a script run by a user with the permission.
>
> But, cron is designed for running commands at certain times, so it 
> might be easier to use that.
>
>> Thanks,
>>
>> -John
>
>
> Hope this helps,
>
>
> Claude