SHUTDOWN()                                      shutdown                                     SHUTDOWN()

NAME

       shutdown - Halt, power-off or reboot the machine

SYNOPSIS

       shutdown [OPTIONS...] [TIME] [WALL...]

DESCRIPTION

       shutdown may be used to halt, power-off or reboot the machine.

       The first argument may be a time string (which is usually "now"). Optionally, this may be followed

       by a wall message to be sent to all logged-in users before going down.

       The time string may either be in the format "hh:mm" for hour/minutes specifying the time to

       execute the shutdown at, specified in 24h clock format. Alternatively it may be in the syntax "+m"

       referring to the specified number of minutes m from now.  "now" is an alias for "+0", i.e. for

       triggering an immediate shutdown. If no time argument is specified, "+1" is implied.

       Note that to specify a wall message you must specify a time argument, too.

       If the time argument is used,  minutes before the system goes down the /run/nologin file is

       created to ensure that further logins shall not be allowed.

OPTIONS

       The following options are understood:

       --help

           Print a short help text and exit.

       -H, --halt

           Halt the machine.

       -P, --poweroff

           Power-off the machine (the default).

       -r, --reboot

           Reboot the machine.

       -h

           Equivalent to --poweroff, unless --halt is specified.

       -k

           Do not halt, power-off, reboot, just write wall message.

       --no-wall

           Do not send wall message before halt, power-off, reboot.

       -c

           Cancel a pending shutdown. This may be used cancel the effect of an invocation of shutdown

           with a time argument that is not "+0" or "now".

EXIT STATUS

       On success,  is returned, a non-zero failure code otherwise.

SEE ALSO

       systemd(), systemctl(), halt(), wall()

systemd                                                                                    SHUTDOWN()

--help：帮助

-H/--half：关闭机器

-P/--poweroff：关闭机器

-r/--reboot：重启机器

-h：与--poweroff一样

-k：不暂停、不关闭、不重启机器，只发送消息给在线的用户

--no-wall：暂停、关闭、重启机器前，不发送消息给在线的用户

-c：取消shutdown命令操作

shutdown –h now             //立即关机

shutdown –h :           //在12:00关机

shutdown + “This System will be shutdown in  minutes”

Broadcast message from root@CentOS6.(/dev/pts/) at : …

The system is going down for maintenance in  minutes!                 //系统提醒

This System will be shutdown in  minutes                              //用户自定义提醒

shutdown –r + “3分钟后关机重启”

Broadcast message from root@CentOS6.(/dev/pts/) at : …

The system is going down for reboot in  minutes!          //系统提醒

3分钟后关机重启                                              //用户自定义提醒

[root@CentOS6 桌面]# shutdown –k  “Waring:maybe the system will be shutdown”

[root@CentOS6 桌面]#

Broadcast message from root@CentOS6.(/dev/pts/) at : …

The system is going down for maintenance in  minutes!

Waring:maybe the system will be shutdown