Experimental Physics and
Industrial Control System

Ben Franksen via Tech-talk <tech-talk at aps.anl.gov> · Wed, 17 Jun 2020 15:01:43 +0200

Am 15.06.20 um 19:43 schrieb Johnson, Andrew N. via Tech-talk:
> On Jun 15, 2020, at 2:23 AM, xiao zhang via Tech-talk
> <tech-talk at aps.anl.gov<mailto:tech-talk at aps.anl.gov>> wrote:
> 
> The only way of starting an IOC I have learned is by running the
> `st.cmd` script, which by default opens an iocsh shell on success. I
> am seeing 2 problems when running IOCs in containers:
> 
> 1. The iocsh shell seems redundant as nobody will actually use it
> when run in containers. A way to start IOC which does not open up
> iocsh is a more light-weight solution.
> 
> I can’t help you with the container side at all, but it is possible
> to build an IOC that doesn’t start the IOC shell, or if you’re using
> one of the softIoc executables, tell that to not start the shell. In
> both cases though the IOC keeps its stdin, stdout and stderr streams
> open, and it will continue to send messages to stdout/stderr.
> 
> If you’re building your own application binary, you have to edit your
> <app>App/src/<app>Main.cpp file, remove the line iocsh(NULL) and
> replace the call to epicsExit(0) with a call to
> epicsThreadExitMain().
> 
> If you’re running the softIoc or softIocPVA executable from Base, you
> can pass that the flag -S (that’s an upper-case letter ’s’ to do the
> same thing as the above.
> 
> The result isn’t really any lighter-weight from the IOC’s perspective
> though, it just means you will have no ability to interact with the
> IOC while it’s running except through CA (or PVA). You can’t close
> stdin, send Control-C through it or use kill -QUIT to stop it, you
> have to use a kill -9 (SIGKILL) to make it die.

I can only agree with Andrew here and I would not recommend running an
IOC without any shell (it doesn't necessarily have to be the 'iocsh').

The standard method run run IOCs on a linux machine is to use provServ.
If configured properly, you can attach to the IOC console using a number
of standard interfaces (TCP port, UNIX domain socket). See 'man
procServ' for details.

Cheers
Ben

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System