Experimental Physics and
Industrial Control System

John Maclean <[email protected]> · Wed, 29 Jan 2003 17:28:44 -0600

I had this problem and have used the screen program as suggested by Eric
Norum.
"screen" is a unix program that may not be on your system but should be
easily available. Our sysadmin people installed it for me very quickly.
It allows you to detach the screen from the ioc without killing the ioc.
You can of course reattach the screen later.
screen is a program with many options, just consult the man page!
However some commands that I've found useful are:
(To simplify things I've assumed "myioc" is a script to start the ioc in
the usual manner)
screen myioc - this will start the ioc attached to a screen. <ctl>a
<ctl>d will detach the screen, leaving the ioc running.
screen -ls - will list the active screen sessions
screen -r pid.tty.hostname - will reattach to the ioc screen.
ssh -t pid.tty.hostname "screen -R" - reattaches to a screen on a
remote machine (not sure this is the exact syntax for this one)
screen -d -m myioc - will start the ioc in detached mode
<ctl>a d - detaches screen from ioc
I've found this to be a really neat tool. It even captures the console
output when your screen is detached and you see it when you reattach. I
have a couple of test stands running for our power supply group using
this technique. There are issues of how you handle multiple iocs on one
machine that I haven't had to consider yet. How do you make sure you
shut down the correct ioc for example?
I hope this helps.
John.

Kevin M. Peterson wrote:

I have a Linux IOC and I am using the main function from
R3.14.1's example App.  After the IOC is initialized iocsh
left in "interactive mode" just like the App. Dev. Guide
describes.
Unfortunately, "shutting down" the Linux IOC dangerously
easy.  It isn't necessary to type the "exit" command; Closing
the terminal window or pressing Ctrl-C do the job with even
less effort.
Is it possible to start the Linux IOC and have it run in the
background?  The Linux IOC seems to be missing the
"non-interacting mode" that all of the vxWorks IOCs have.

Thanks ahead of time,
Kevin Peterson

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System