shutdown命令

[haoqimin@localhost root]$ 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
　-H    停止机器
  -P    关闭电源
　-r    重启
  -h    相当于--poweroff和--halt
　-k    模拟关机，向登录者发送关机警告
　-c [说明信息]      取消关机