busybox/shell/ash_test/ash-signals/signal2.tests

#!/bin/sh

$THIS_SH -c '
cleanup() {
    echo "child exits as expected"
    exit
}
trap cleanup HUP
echo "child sleeps"
sleep 1
echo "BAD exit from child!"
' &

child=$!
sleep 0.1 # let child install handler first
kill -HUP $child
wait
echo "parent exits"