我们会遇到很多进入后台系统的时候，会根据选择，进入不同的系统，下面是一个简单的例子：
#!/bin/sh
function menu ()
{
cat << EOF
----------------------------------------
|************Menu Home Page ************|
----------------------------------------
`echo -e "\033[35m 1)Person\033[0m"`
`echo -e "\033[35m 2)Admin\033[0m"`
`echo -e "\033[35m 3)Menu\033[0m"`
`echo -e "\033[35m 4)Quit\033[0m"`
EOF
read -p "input you num：" num1
case $num1 in
1)
echo "Welcome to people!!"
person_menu
;;
2)
echo "Welcome to admin!!"
admin_menu
;;
3)
clear
menu
;;
4)
exit 0
;;
*)
echo "Input Error ,Please again !!!"
exit 1
;;
esac
}
function person_menu ()
{
cat << EOF
----------------------------------------
|***************PERSON****************|
----------------------------------------
`echo -e "\033[35m 1)Zhangsan\033[0m"`
`echo -e "\033[35m 2)Lisi\033[0m"`
`echo -e "\033[35m 3)Wangwu\033[0m"`
`echo -e "\033[35m 4)Back\033[0m"`
EOF
read -p "input you num：" num2
case $num2 in
1)
echo "Welcome to Zhangsan !!"
person_menu
;;
2)
echo "Welcome to Lisi !!"
person_menu
;;
3)
echo "Welcome to Wangwu !!"
person_menu
;;
4)
clear
menu
;;
*)
echo "the is Fail!!"
person_menu
esac
}
function admin_menu ()
{
cat << EOF
----------------------------------------
|***************ADMIN****************|
----------------------------------------
`echo -e "\033[35m 1)Admin\033[0m"`
`echo -e "\033[35m 2)Admin1\033[0m"`
`echo -e "\033[35m 3)Admin2\033[0m"`
`echo -e "\033[35m 4)Back\033[0m"`
EOF
read -p "input you num：" num3
case $num3 in
1)
echo "Welcome to Admin !!"
admin_menu
;;
2)
echo "Welcome to Admin1 !!"
admin_menu
;;
3)
echo "Welcome to Admin2 !!"
admin_menu
;;
4)
clear
menu
;;
*)
echo "the is Fail!!"
admin_menu
esac
}
menu
运行结果：
根据选择进入不同的选项