Shell编程进阶 1.7 case选择

逻辑判断的格式

vim case.sh

#!/bin/bash
read -p "please input a number:" n
m=$[$n%2]
case $m in
        1)
                echo " It is a jishu'"
                ;;
        0)
                echo " It is a oushu."
                ;;
        *)
                echo " Not is a jishu and oushu."
esac

输入一串字符 赋值$n

$m=$n除以2

判断$m 

等于1

输出这是个奇数

等于0

输出这是个偶数

等于其他

输出这不是奇数和偶数

#!/bin/bash
read -p "please input a number:" n
w=`echo $n |sed 's/[0-9]//g'`
if [ -n "$w" ]
then
        echo "Not is a number,please input a number."
else
        echo $n
fi
m=$[$n%2]
case $m in
        1)
                echo " It is a jishu'"
                ;;
        0)
                echo " It is a oushu."
                ;;
        *)
                echo " Not is a jishu and oushu."
esac