定时关机命令练习习作，主要是对shell,shutdown的练习-Timing shutdown command to practice exercises, mainly on the shell, shutdown exercises

shell脚本，实现的是嵌入式常见的脚本查寻，可以使用这个脚本来进行嵌入式的其他应用练习。-shell scr ipt, to achieve a common scr ipt embedded search, you can use this scr ipt to be embedded in other applications exercises.