How to kill child processes in Bash?

Question

I am trying to do an operation in linux trying to burn cpu using openssl speed

this is my code from netflix simian army

#!/bin/bash
# Script for BurnCpu Chaos Monkey

cat << EOF > /tmp/infiniteburn.sh
#!/bin/bash
while true;
   do openssl speed;
done
EOF

# 32 parallel 100% CPU tasks should hit even the biggest EC2 instances
for i in {1..32}
do
  nohup /bin/bash /tmp/infiniteburn.sh &
done

so this is Netflix simian army code to do burn cpu, this executes properly but the issue is I cannot kill all 32 processes, I tried everything

pkill -f pid/process name
killall -9 pid/process name
etc.,

the only successful way I killed the process is through killing it via user

pkill -u username

How can I kill these process without using username?

any help is greatly appreciated

Possibly related/maybe a duplicate: [Best way to kill all child processes](http://stackoverflow.com/q/392022). Closely related is [How to kill all subprocesses of shell?](http://stackoverflow.com/q/2618403/) Someone with more Bash experience then me who understands the subtleties will have to decide. — jww, Nov 08 '16 at 04:26

score 4 · Accepted Answer · answered Nov 08 '16 at 03:46

finally, I found a solution to my own question,

kill -- -$(ps -o pgid= $PID | grep -o [0-9]*)

where PID is the process ID of any of the one processes running, this works fine but I am open to hear any other options available

source: http://fibrevillage.com/sysadmin/237-ways-to-kill-parent-and-child-processes-in-one-command

score 3 · Answer 2 · answered Nov 08 '16 at 02:07

3

Killing a process doesn't automatically kill its children. Killing your bash script won't kill the openssl speed processes.

You can either cast a wider net with your kill call, which is what you're doing with pkill -u. Or you could use trap in your script and add an error handler.

cleanup() {
    # kill children
}

trap cleanup EXIT

answered Nov 08 '16 at 02:07

John Kugelman

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You can either cast a wider net with your kill call??? could you please provide more info on this, – Coding Ninja Nov 08 '16 at 03:06

score 0 · Answer 3 · answered May 30 '19 at 17:01

I had a similar problem and solution where I needed to kill a NodeJS server after some amount of time.

To do this, I enabled Job control, and killed async processes by group id with jobs:

set -m
./node_modules/.bin/node src/index.js &
sleep 2

kill -- -$(jobs -p)

How to kill child processes in Bash?

3 Answers3