Howto terminate all running subshells?

[flux242]

I have a script that starts a subshell

#!/bin/sh

local SSPID

clean_exit() {
  #here the subshell shall be killed
  exit 0
}

trap clean_exit INT TERM EXIT

while true
do
  #open a subshell that waits for events, let's say user input
  cmd=$(read)
  #do something with the $cmd
  ...
done

so the script waits in the loop for the subshell to finish then does processing and starts over. If I kill the script the subshell is not killed. So I can trap the TERM event and do some cleaning but I need to know the subshell process id.

I'm using busybox so ps does not accept any parameters
I cannot source subshell so it can access its parent environment

So how can it done? Thanks

[barriehie]

So can you get the subshell to do something with $$, the PID?

[flux242]

what should the subshell do with its parent PID?