2021-07-30 shell 多条件选择语句--＞case语法和示例

语法结构：

case variable in
value_1)
    statement1
    statement2
    ...
    statementn;;
value_2)
    statement1
    statement2
    ...
    statementn;;
value_3)
    statement1
    statement2
    ...
    statementn;;
value_n)
    statement1
    statement2
    ...
    statementn;;
    *)
    statement1
    statement2
    ...
    statementn;;
esac

 示例：键盘输入任意字符，判断字符类型

#！/bin/bash

echo "please press a hit key:"
read keypress
case keypress in
    [[:lower:]])
        echo "Lowercase letter."
    [[:upper:]])
        echo "Uppercase letter."
    [0-9]
        echo "digit."
*)
    echo "other press."
esac

运行结果：

[root@iZ2ze098m9sg0tui8p2eacZ zpl]# ./case.sh 

please press a hit key：K

uppercase letter