[LAU] Running a JACK application with cron et al.

[Len Ovens]

On Tue, 21 Jul 2015, Chris Caudle wrote:

> On Tue, July 21, 2015 1:16 am, F. Silvain wrote:
>> is there a way to do it? I tried, but didnt get any sound. I suspect, that
>> cron doesn't use the user, who defined the task to be run?
>
> According to the crontab man page, there should be a crontab file per
> user, and the tasks will be run as the user who owns the crontab:
>
> A crontab file contains instructions to the cron(8) daemon of the general
> form: "run this command at this time on this date". Each user has their
> own crontab, and commands in any given crontab will be executed as the
> user who owns the crontab.

That is my understanding as well. The user just types crontab -e to edit 
their crontab.
>
>> My system is Debian Squeeze, my JACK is 0.121.3 .
>> My scheduler is anacron
>
> This is in the "Disadvantages" paragraph in the Wikipedia description of
> anacron:
> Only the system administrator can configure anacron tasks. In contrast,
> cron allows non-admin users to configure scheduled tasks.

So far as I know anacron uses cron, so if you have one you have the 
other... at least with my ubuntustudio setup that is true.

My question becomes why stop jack? I run jack 24/7 here with no problems. 
I have done so for over 2 years now. Pulse audio sees jack as it's audio 
interface and jack allows changing latency as it runs (well jack 2 does 
for sure, but I have not seen anything that says jack1 doesn't). If I 
lower the latency past what pulse deals well with, I unload the pulse 
bridge and pulse "quietly" uses it's dummy sink till I reload the bridge.
Pulse uses very little cpu in this mode... even less if you don't stream 
audio at it.


--
Len Ovens
www.ovenwerks.net