pre_install() {
  /bin/true
}

post_install() {
  echo "-- You should add dkfilter user and group"
  /bin/true
}

pre_upgrade() {
  /bin/true
}

post_upgrade() {
  /bin/true
}

pre_remove() {
  /bin/true
}

post_remove() {
  echo "-- You may remove dkfilter user and group"
  /bin/true
}

op=$1
shift
$op $*