Re: "Inject" code into IOC startup files?

[Timo Korhonen via Tech-talk <tech-talk at aps.anl.gov>]

Hello Eddy,

 

This, now merged PR might be interesting for you: https://github.com/epics-base/epics-base/pull/558

 

Will be in next release.

There was earlier work by Dirk Zimoch that was the origin for this PR and the work, named afterInit, in this repository: https://github.com/paulscherrerinstitute/iocsh_utilities

 

Cheers,

 

Timo

 

From: Tech-talk <tech-talk-bounces at aps.anl.gov> on behalf of "Blomley, Edmund (IBPT) via Tech-talk" <tech-talk at aps.anl.gov>
Reply to: "Blomley, Edmund (IBPT)" <edmund.blomley at kit.edu>
Date: Thursday, 26 June 2025 at 11:27
To: EPICS Tech Talk <tech-talk at aps.anl.gov>
Subject: "Inject" code into IOC startup files?

 

Dear all,

 

Most of our IOCs use the (current?) "default" IOC structure created by the `makeBaseApp.pl` script. 

 

Now there are several scenarios where we currently add the same line of code or same „functionality" to each start up file "by convention“. (For new IOCs we have some scripts adjusting the results of `makeBaseApp.pl` from the beginning).

 

One example: we export the list of PVs after IOC init. Because we use a custom ENV variables set by our systemd script for each IOC, this line is 100% identical for each IOC and looks something like that:

 

cd ${TOP}/iocBoot/${IOC}

iocInit

# Write list of records.

dbl > "${EPICS_AUTOPVLIST_IOC_FILE}"

 

The second scenario is to do some things _before_ IOC init: For example load the iocStats records.

 

Adding these lines of code once is one thing… But for example, now I would like to add recCaster to each startup file… if that is done, we might also can get rid of the dbl export…

 

So the question: Is there a way to define some generic „hook-in“ behavior which allows to „add code“ _before_ AND _after_ IOC init, where the actual code is managed outside of the IOC structure and could be used across multiple IOCs? Also due to our orchestration and systemd files, we can do some „customization“ during IOC deployment if necessary.

 

Our current „brain-storming“ idea is maybe through a module, we could add an IOC shell function that allows registering files for later execution. But before we start working on that… other ideas? Is there already a built-in option? Have other labs already created some custom code to allow for something like that?

 

Cheers

Eddy