How to kill zombie process [closed]

I launched my program in the foreground (a daemon program), and then I killed it with

kill -9

, but I get a zombie remaining and I m not able to kill it with

kill -9

. How to kill a zombie process?

If the zombie is a dead process (already killed), how I remove it from the output of

ps aux

?

root@OpenWrt:~# anyprogramd &
root@OpenWrt:~# ps aux | grep anyprogram
 1163 root      2552 S    anyprogramd
 1167 root      2552 S    anyprogramd
 1169 root      2552 S    anyprogramd
 1170 root      2552 S    anyprogramd
10101 root       944 S    grep anyprogram
root@OpenWrt:~# pidof anyprogramd
1170 1169 1167 1163
root@OpenWrt:~# kill -9 1170 1169 1167 1163
root@OpenWrt:~# ps aux |grep anyprogram
 1163 root         0 Z    [cwmpd]
root@OpenWrt:~# kill -9 1163
root@OpenWrt:~# ps aux |grep anyprogram
 1163 root         0 Z    [cwmpd]

2) Here a great tip from another user (Thxs Bill Dandreta):
Sometimes

kill -9 <pid>
will not kill a process. Run
ps -xal
the 4rd field is the parent process, kill all of a zombie’s parents and the zombie dies!
Example
4 0 18581 31706 17 0 2664 1236 wait S ? 0:00 sh -c /usr/bin/gcc -fomit-frame-pointer -O -mfpmat
4 0 18582 18581 17 0 2064 828 wait S ? 0:00 /usr/i686-pc-linux-gnu/gcc-bin/3.3.6/gcc -fomit-fr
4 0 18583 18582 21 0 6684 3100 - R ? 0:00 /usr/lib/gcc-lib/i686-pc-linux-gnu/3.3.6/cc1 -quie

18581
,
18582
,
18583
 are zombies –
kill -9 18581 18582 18583
has no effect.
kill -9 31706
removes the zombies.

2) Here a great tip from another user (Thxs Bill Dandreta):
Sometimes

kill -9 <pid>
will not kill a process. Run
ps -xal
the 4rd field is the parent process, kill all of a zombie’s parents and the zombie dies!
Example
4 0 18581 31706 17 0 2664 1236 wait S ? 0:00 sh -c /usr/bin/gcc -fomit-frame-pointer -O -mfpmat
4 0 18582 18581 17 0 2064 828 wait S ? 0:00 /usr/i686-pc-linux-gnu/gcc-bin/3.3.6/gcc -fomit-fr
4 0 18583 18582 21 0 6684 3100 - R ? 0:00 /usr/lib/gcc-lib/i686-pc-linux-gnu/3.3.6/cc1 -quie

18581
,
18582
,
18583
 are zombies –
kill -9 18581 18582 18583
has no effect.
kill -9 31706
removes the zombies.