求教：一个linuxshell编程题

what popo

编写一个shell程序,设计如下的菜单,并实现其功能。
----------------------------------------------------------
  User:xxxx      Host:xxxx   Date: xx/xx/xxxx
-----------------------------------------------------------
         1.List files in current directoy
         2.Display current time
         3.See who is on system
         4.find files have been accessed during 24hours
         Q.Exit  
-----------------------------------------------------------
         Your Choice[1,2,3,4,Q]

xinkeren

#!/bin/sh
user=$(who am i)
host=$(hostname)
date=$(date +H%+D%)
echo "------------------------------------------
useruser  Hosthost datedate
---------------------------------------------------"
echo  
1.List files in current directoy
2.Display current time
3.See who is on system
4.find files have been accessed during 24hours
Q.Exit
---------------------------------------------------------
read choose
case "$choose"
     in

1)command;;
2)command2;;
3)command 3;;
4)command4;;
q|Q)exit 0;;
*)echo "usage some error";;
用printf会好一些
esac

what popo

command能不能具体点，谢啦