init

#!/bin/sh

SYSTEMCTL_PY="systemctl3.py"

get_cmd(){
  local cmd="$1"
  command -v "$cmd" || printf "${0%/*}/$cmd"
}

SYSTEMCTL=$(get_cmd $SYSTEMCTL_PY)

usage() {
  cat <<EOF
${0##*/} [OPTIONS...] COMMAND

Send control commands to the init daemon.

Commands:
  0              Power-off the machine
  6              Reboot the machine
  2, 3, 4, 5     Start runlevelX.target unit
  1, s, S        Enter rescue mode
  q, Q           Reload init daemon configuration
  u, U           Reexecute init daemon

Options:
     --help      Show this help

This is a fake init script, See $(readlink -f ${0}) file for details.
EOF
}

prepare(){
  [ ! -L "/tmp/run" ] && ln -sfr /tmp /tmp/run
  [ ! -x $SYSTEMCTL ] && die "${0##*/}: command not found: $SYSTEMCTL_PY"
  [ ! -x /usr/bin/python3 ] && die "${0##*/}: command not found: python3"
}

system_init(){
  prepare
  mount -a -v
}

case $1 in
  -h|--help)  usage && exit 0     ;;
  0)  COMMAND=$(get_cmd poweroff) ;;
  6)  COMMAND=$(get_cmd reboot)   ;;
  1|s|S)  COMMAND="/bin/sh"       ;;
  q|Q|u|U)
    SHELL="/bin/sh $SYSTEMCTL halt \
    && $SYSTEMCTL init" && exit 0 ;;
  *)
    system_init
    COMMAND="$SYSTEMCTL init"     ;;
esac

[ "$(id -u)" -ne 0 ] && printf "Must be root\n" && exit 1
exec $COMMAND