topic Re: ksh scripting in Operating System - HP-UX

ksh scripting

Klaas D. Eenkhoorn — Fri, 19 Dec 2003 07:07:44 GMT

Dear all,

I have a question wich breakes my mind.

I have a script monitoring a log file for specific messages.
I use the construction:

tail -f $logfile | while read line
do
case $line in
ORA-*)
echo "Fout in logfile: $line
;;
esac
done

This script, written in KSH will run until the system is stopped or until i kill the script.
If i do this with kill -15 PID (of the script)
Tail stays behind in the process table with a parent process of 1

How do i stop this process together with my script ?

Kl@@s

Re: ksh scripting

Mark Grant — Fri, 19 Dec 2003 07:17:12 GMT

Kill the PID of the "tail" instead. This will also cause the script to finish.

Re: ksh scripting

Kent Ostby — Fri, 19 Dec 2003 07:18:54 GMT

From the man page on the -f option:

(tail enters
an endless loop wherein it sleeps for one second
then attempts to read and copy further records
from the input file)

So thats why there is a problem. I'm not sure of a solution yet :-) I'll continue looking.

Re: ksh scripting

Jean-Luc Oudart — Fri, 19 Dec 2003 07:19:54 GMT

The parent PID of tail is your script.
you shouild be able to find both PID and kill them all in one go
kill -15 PID1 PID2

Regards,
Jean-Luc

Re: ksh scripting

Klaas D. Eenkhoorn — Fri, 19 Dec 2003 07:21:04 GMT

Is it realy that simpel . . . :`-(
Well it's friday my mind seems to be on leaf allready.

Kl@@S

Re: ksh scripting

MarkSyder — Fri, 19 Dec 2003 07:21:34 GMT

Have you tried kill -9?

Mark Syder (like the drink but spelt different)

Re: ksh scripting

Michael Schulte zur Sur — Fri, 19 Dec 2003 12:12:49 GMT

Hi,

the script is run by who? By an interactive shell, with nohup or what? When you run it with nohup, you will have to kill the tail. Of course you can allways kill the shell too.

greetings,

Michael

Re: ksh scripting

Paula J Frazer-Campbell — Fri, 19 Dec 2003 12:27:11 GMT

Mark

-9 ??

Sledgehammer to catch a butterfly,
Use kill -9 as the very very last resort.

Paula

Re: ksh scripting

Mark Greene_1 — Fri, 19 Dec 2003 13:40:23 GMT

Klaas,

As the other Mark G wrote, kill the "tail" process. It should go away with just a "kill". If you have to use a -9, you have other problems; however, your script is hardly that complex so you ought not have to resort to the -9.

mark

Re: ksh scripting

Rodney Hills — Fri, 19 Dec 2003 15:02:29 GMT

A little know fact about the "kill" command is that if you put a "-" in front of the pid, it will kill all processes that in that "process group".

$ ps -ef | grep tail
rhills 6725 6723 0 11:58:12 pts/tTb 0:00 tail -f /var/adm/syslog/syslog.log
rhills 6730 5560 2 11:58:18 pts/tt 0:00 grep tail
pegasus rhills $ kill -15 -6723
pegasus rhills $ ps -ef | grep tail
rhills 6744 5560 0 11:58:32 pts/tt 0:00 grep tail

I killed the pid 6723 (ksh parent of tail child) and it not only killed the ksh script, but also the tail.

Another alternative is to put a "trap" in your script, that when the ksh script is killed, it then kills the tail command.

HTH

-- Rod Hills

Re: ksh scripting

Laurent Menase — Fri, 19 Dec 2003 18:17:32 GMT

kill -15 -PID

with -PID you send the signal to all the proces s group.

this ksh is not interactif so the other are run in its process group.

Re: ksh scripting

Brian Markus — Fri, 19 Dec 2003 19:03:33 GMT

I use this:

export JOBNUM=$$

$$ is the PID of the current script. You can store that and kill it later when ever you're ready.

Hope this helps

-Brian.