$ curl cheat.sh/
# telinit
# Change SysV runlevel.
# Since the concept SysV runlevels is obsolete the runlevel requests will be transparently translated into systemd unit activation requests.
# More information: <https://manned.org/telinit>.

# Power off the machine:
telinit 0

# Reboot the machine:
telinit 6

# Change SysV run level:
telinit 2|3|4|5

# Change to rescue mode:
telinit 1

# Reload daemon configuration:
telinit q

# Do not send a wall message before reboot/power-off (6/0):
telinit --no-wall value

$
Follow @igor_chubin cheat.sh tldr