I have a java service that needs to be run in a gnu screen session so that I can -r into it to access it's interactive shell. I would like this to run at start-up. More importantly, it crashes frequently so I need the service to restart itself when it crashes.

How do I go about doing this myself? My previous experience with shell scripting amounts to putting ./service in a file and marking it executable.

This will be running on a FreeBSD server, but I might put it on a Linux server soon also. So any caveats on the differences would be useful information.

Thank you

1. To restart service you can use simple bash script with infinite loop. It should check if your script is running and restart it if not.
2. Simplest way to run script at startup is init.d (for Linux) or rc.d (for FreeBSD) script with dtach. There a lot of examples.
It's something like screen but with minimal functionality.

I've used dtach before, it shouldn't take much to re-familiarize myself. The loop should be easy enough, but how do I perform a check to see if the process is running?

For Linux:
FreeBSD version:

1 members found this post helpful.

Actually ps aux works fine in freebsd too.

I figured I'd need some kind of way to set the pid and check for it. Your simpler solution is much better and so obvious I feel foolish for not thinking of it myself.

When the process dies so does the dtach session right?

I suppose so.

This works perfectly. Thanks a lot.