case语句

case条件语句的语法格式：

case "变量" in

　　value 1)

　　　　指令 1...

　　　　;;

　　value 2)

　　　　指令 2...

　　　　;;

　　value 3)

　　　　指令 3...

　　　　;;

　　*)

　　　　指令 ...
esac

实例：

#!/bin/bash

RED_COLOR="E[1;31m"
GREEN_COLOR="E[1;32m"
YELLOW_COLOR="E[1;33m"
BLUE_COLOR="E[1;34m"
RES="E[0m"

cat << END
        =============================
        1.apple
        2.pear
        3.banana
        4.cherry
        =============================
END

read -p "Please input a number to choice." num

case $num in
        1)
                echo -e "${RED_COLOR}apple${RES}"
                ;;
        2)
                echo -e "${GREEN_COLOR}pear${RES}"
                ;;
        3)
                echo -e "${YELLOW_COLOR}banana${RES}"
                ;;
        4)
                echo -e "${BLUE_COLOR}cherry${RES}"
                ;;
        *)
                echo "Must be input {1|2|3|4}"
esac
~      

运行结果：

[root@rhel6 script]# bash case02.py 
        =============================
        1.apple
        2.pear
        3.banana
        4.cherry
        =============================
Please input a number to choice.1
apple
[root@rhel6 script]# bash case02.py 
        =============================
        1.apple
        2.pear
        3.banana
        4.cherry
        =============================
Please input a number to choice.2
pear
[root@rhel6 script]# bash case02.py 
        =============================
        1.apple
        2.pear
        3.banana
        4.cherry
        =============================
Please input a number to choice.3
banana
[root@rhel6 script]# bash case02.py 
        =============================
        1.apple
        2.pear
        3.banana
        4.cherry
        =============================
Please input a number to choice.4
cherry