Trying to kill process by shell scripting

Question

I want to kill process through shell scripting it is giving me error. Here is what i tried so far:

When i try to kill memcache it give me error like "kill: No such process" , i used below command:

ps -ef | grep "memcache" | awk '{print $2}' | xargs kill;

or if try like below:

kill -9 $(pidof memcache)

i get error like below:": arguments must be process or job IDs"

When i run directly on command prompt process is running:

ring@ubuntu:~/parasol$ ps aux | grep memcache     
memcache   873  0.0  0.0 323220  1188 ?        Sl   22:56   0:00 /usr/bin/memcached -m 64 -p 11211 -u memcache -l 127.0.0.1
ring      1714  0.0  0.0   9384   920 pts/0    S+   23:45   0:00 grep --color=auto memcache

I reff to https://askubuntu.com/questions/239923/shell-script-to-9-kill-based-on-name AND Shell script to capture Process ID and kill it if exist

My Ubuntu Version:

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=12.04
DISTRIB_CODENAME=precise
DISTRIB_DESCRIPTION="Ubuntu 12.04.2 LTS"
NAME="Ubuntu"
VERSION="12.04.2 LTS, Precise Pangolin"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu precise (12.04.2 LTS)"
VERSION_ID="12.04"

What is result if `pidof memcache` or `ps -ef | grep "memcache" | awk '{print $2}'`? Looks ok. — keltar, Oct 31 '13 at 06:50
Acutally `ps -ef | grep memcache` will give two lines.. so you can go this way `ps -ef | grep memcache | grep -v "grep" | awk '{print $2}' | xargs kill;` — Ashish, Oct 31 '13 at 07:16
@Ashish: it gives error ": No such file or directory", but when i run ps -ef | grep memcache | grep -v "grep" it gives only one process. Problem with awk... — Suresh Kamrushi, Oct 31 '13 at 07:22
I had linux mint using its GUI so there is process gnome terminal i executed `ps -ef | grep gnome-terminal | grep -v "grep" | awk '{print $2}'` and got 2803 which is the PID — Ashish, Oct 31 '13 at 07:26

Ashish · Accepted Answer · 2013-10-31T07:42:43.103

9

Acutally

ps -ef | grep memcache

will give two lines..

so you can go this way

ps -ef | grep memcache | grep -v "grep" | awk '{print $2}' | xargs kill;

This can get you exact one PID

if I has to do I would break it in 2 lines in start

#!/bin/bash
PID=`ps -ef | grep memcache | grep -v "grep" | awk '{print $2}'`
echo $PID
#to check PID is right
kill -9 $PID

save it in scrip files say test.sh

then on terminal

chmod +x test.sh

then

./test.sh

edited Oct 31 '13 at 07:42

answered Oct 31 '13 at 07:21

Ashish

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it give error at line where i am storing PID as line 3: PID: command not found – Suresh Kamrushi Oct 31 '13 at 07:27
I am getting pid but not able to store in variable. – Suresh Kamrushi Oct 31 '13 at 07:29
what is o/p `ps -ef | grep memcache | grep -v "grep" | awk '{print $2}'` – Ashish Oct 31 '13 at 07:38
it gives me process id. – Suresh Kamrushi Oct 31 '13 at 07:40
you make a script with say test.sh with copy above lines in it and run script – Ashish Oct 31 '13 at 07:41
copied now, it echo pid. But while killing it gives ring@ubuntu:~/parasol$ bash my_test_batch.sh 873 : arguments must be process or job IDs ring@ubuntu:~/parasol$ – Suresh Kamrushi Oct 31 '13 at 07:43
Please try it on some other process and check – Ashish Oct 31 '13 at 07:46
3

Gaaa, [useless uses of `grep`](http://partmaps.org/era/unix/award.html#grep) galore! You mean `ps -ef | awk '/[m]emcache/{print$2}'`. – tripleee Oct 31 '13 at 08:02
2

useless uses of `ps`, `grep` and `awk` galore! This can be replaced by `pkill -f -9 memcache` – jlliagre Oct 31 '13 at 14:46

score 3 · Answer 2 · answered Oct 31 '13 at 07:04

3

You can use these commands: pkill memcached or pgrep memcached | xargs kill -9 or killall memcached.

pgrep, pkill - look up or signal processes based on name and other attributes.

answered Oct 31 '13 at 07:04

BlackMamba

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@SureshKamrushi If you not use the parameter `-9`, is it work? – BlackMamba Oct 31 '13 at 07:10
without -9 it give error "kill: Operation not permitted my_test_batch.sh: line 3: $'\r': command not found" – Suresh Kamrushi Oct 31 '13 at 07:13
@SureshKamrushi Sorry i cann't help you. What the version of your linux? The other two commands work or not? – BlackMamba Oct 31 '13 at 07:18
Thanks BlackMamba for your time and efforts. – Suresh Kamrushi Oct 31 '13 at 07:51
The error messages seem to indicate that you somehow get a DOS carriage return in there somewhere. Irrespective of that, this is the Right Answer. +1 – tripleee Oct 31 '13 at 08:04
@tripleee regardless of the carriage return issue, this answer is still incorrect, i.e. it won't catch memcached. – jlliagre Oct 31 '13 at 14:42

score 2 · Answer 3 · answered Oct 31 '13 at 07:22

2

Your first command might be killing itself before having chance to kill the target processes.

For a reliable way, run pkill /usr/bin/memcached or pkill -9 /usr/bin/memcached although the latter is a bad practice.

answered Oct 31 '13 at 07:22

jlliagre

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Some programmer dude · Answer 4 · 2013-10-31T07:05:46.200

1

For the first command, you see that there are two processes that matches the pattern you grep for. The actual memcached process and your grep process. That is probably the reason for the error of the first command line.

Try narrowing the search down, for example by grepping for e.g. "^memcache.*/usr/bin/memcached".

The problem with the second error is that you're calling pidof with the username instead of the process name, so the command is essentially kill -9 without any process id. Try instead e.g. pidof memcached to get the process id of the correct process.

edited Oct 31 '13 at 07:05

answered Oct 31 '13 at 06:51

Some programmer dude

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I try like this: sudo ps -ef | grep ^memcache.*/usr/bin/memcached | awk '{print $2}' | xargs kill; giving error: kill: Operation not permitted my_test_batch.sh: line 3: $'\r': command not found – Suresh Kamrushi Oct 31 '13 at 07:11
@SureshKamrushi Can you try with the quotes around the `grep` regex? – Some programmer dude Oct 31 '13 at 07:12
with quotes it give error ": No such file or directory". But i have memcached directory in usr/bin/ – Suresh Kamrushi Oct 31 '13 at 07:17

score 0 · Answer 5 · answered Oct 31 '13 at 11:25

ps -ef | grep "memcache" | awk '{print $2}' | xargs kill; 
PID=`ps -ef | grep memcache | grep -v "grep" | awk '{print $2}'`
#...

First, you could use cut instead of awk in this case. No need to use a tank to kill a fly ;)

Then, why is it necessary to brutally kill memcache? You have a daemon to stop it :

/etc/init.d/memcached stop
service memcached stop

Trying to kill process by shell scripting

5 Answers5