processes remain after I have logged out!

drgowans · 11-11-2003, 09:44 AM

I am running Redhat 9, with GNOME.

I wrote a little script that runs in the background after I login. I placed it in my '.login' file, like this:

...
/genesis/get_mon_lx &
...

When I look at it with ps -ef, if will look like this:

image 5067 5013 0 08:33 pts/0 0:00:00 /bin/sh /genesis/get_mon_lx

This is the content of the program "get_mon_lx":

----------
while true
do
/genesis/snapshot_lx.py
sleep 1200
done
----------

The program is runs is a python program that runs for a few seconds, checks a couple processes, writes to a log file. It then waits for about 20 minutes, and runs again.

There are multiple users on this machine, and each login runs this program.

The problem is when a user logs out. This is what the process list looked like this morning:

image 4132 1 0 Nov 10 ? 0:00:00 /bin/sh /genesis/get_mon_lx
image 3144 1 0 Nov 10 ? 0:00:00 /bin/sh /genesis/get_mon_lx
image 5422 1 0 Nov 10 ? 0:00:00 /bin/sh /genesis/get_mon_lx
image 12332 1 0 Nov 10 ? 0:00:00 /bin/sh /genesis/get_mon_lx
image 2378 1 0 Nov 10 ? 0:00:00 /bin/sh /genesis/get_mon_lx
image 8733 4333 0 07:34 pts/0 0:00:00 /bin/sh /genesis/get_mon_lx

Everything that had been started the day before was still there! Why doesn't this process get killed on logout? What is going wrong? Any ideas? On other machines, I have had much cleaner logouts (HP-UX for example, always cleans up impeccably after a logout)

Help greatly appreciated. I can't have these left behind on every logout.

Thanks!

jim mcnamara · 11-11-2003, 10:12 AM

One possible solution:

Code:

while [  /genesis/snapshot_lx.py ]
do
  ps -p $PPID > /dev/null
  if [ $? -eq 1 ]; then
     break;
  fi
  sleep 1200
done
exit

Do something to check for the existence of the parent process so it will exit when the parent process goes away. $PPID is the parent pid.

drgowans · 11-11-2003, 12:56 PM

Thanks Jim,

That was what I ended up doing, except I pulled out the shell script altogether and just had the python program loop, then check the parent, etc in the same way. That seems to be working very well.

Do you or anyone know why it doesn't get killed automatically when the user logs out? A feature or a bug?

Thanks!

warath · 11-11-2003, 02:43 PM

The process doesn't die because you told it NOT to. The '&' symbol sends the process to the background. I forget the command off the top of my head that will bring it to the foreground again. Once the program is sent to the 'background' it will stay there until you kill it, or it finishes, or you bring it back to the foreground.

jim mcnamara · 11-11-2003, 07:54 PM

fg brings the process to the foreground.

And, he didn't

Code:

nohup processname &

which is really what you need to do to make a process relatively bulletproof.

aqoliveira · 11-12-2003, 03:39 AM

Howzit

well instead of running the process/script in the bg why not creat a crontab to execute that script every 20min....Just a alternative

chow