Bash kill shell script running in background

Kill a running script using the parent process id.

$ cat myscript.sh 
while :; do
    date
    sleep 1
done

$ bash myscript.sh
Sun Dec 10 00:00:00 PST 2017
Sun Dec 10 00:00:01 PST 2017
Sun Dec 10 00:00:02 PST 2017
Sun Dec 10 00:00:03 PST 2017
...

Find the parent process id in the 3rd column. It contains the value for the PPID (parent process id).

$ ps lux | head -1
  UID   PID  PPID CPU PRI NI      VSZ    RSS WCHAN  STAT   TT       TIME COMMAND          USER  %CPU %MEM STARTED

$ ps lux | grep sleep
  501 16357 16313   0  31  0  4267768   1000 -      S+   s002    0:00.01 sleep 1          user   0.1  0.0 00:00AM
  501 16359 15647   0  31  0  4259052    288 -      R+   s001    0:00.00 grep sleep       user   0.0  0.0 00:00AM

Use the kill command on the PPID and it will stop the child process. Ignore the line containing the process ids for the grep command.

$ kill 16313

The child process is terminated.

...
Sun Dec 10 00:00:04 PST 2017
Sun Dec 10 00:00:05 PST 2017
Sun Dec 10 00:00:06 PST 2017
Sun Dec 10 00:00:07 PST 2017
Sun Dec 10 00:00:08 PST 2017
Terminated: 15

If the process is not terminated, you might try -9 or sudo.

$ kill -9 $ppid
$ sudo kill $ppid
$ sudo kill -9 $ppid