Ubuntu18.04之shutdown开/关机

 1.shutdown命令详解

# shutdown --help
shutdown [OPTIONS...] [TIME] [WALL...]

Shut down the system.

     --help      Show this help
  -H --halt      Halt the machine
  -P --poweroff  Power-off the machine
  -r --reboot    Reboot the machine
  -h             Equivalent to --poweroff, overridden by --halt
  -k             Don't halt/power-off/reboot, just send warnings
     --no-wall   Don't send wall message before halt/power-off/reboot
  -c             Cancel a pending shutdown

2.shutdown开机、关机

<1>.shutdown无任何参数时，默认一分钟后开机或者关机

延时1分钟后关机
# shutdown -P

延时1分钟重启
# shutdown -r 



延时15分钟关机
# shutdown -P +15 

延时15分钟重启
# shutdown -r +15



立刻关机
# shutdown -P 0

立刻重启
# shutdonw -r 0


取消关机或重启
# shutdown -c