Kill process tree - shell function and script.

killtree-multipass.sh

#!/bin/sh

KILLSIG=""

walktree() { local p=""; for p in "$@"; do walktree $(pgrep -P "$p"); echo $p; done; }

test "${1#-}" != "$1" && KILLSIG="$1"                   && shift
test        $# = "0"  && echo "Usage: ${0##*/} pid ..." && exit

PIDS="$(walktree "$@")"

while kill $KILLSIG $PIDS; do sleep 0.2; done
exit 0

## END ##

killtree.sh

#!/bin/sh

killtree() {
    local KILLSIG=""
    test "${1#-}" = "$1" || { KILLSIG="$1"; shift; }
    test $# = "0" && echo "Usage: ${0##*/} pid ..." && return 1
    local p=""; for p in "$@"; do killtree $(pgrep -P "$p"); kill $KILLSIG "$p"; done;
}

killtree "$@"