Abyss

三、         赋值拼字符串

vi second

#!/bin/sh

num=2

echo “this is $numnd”

echo “this is $num nd”

echo “this is {$num}nd”

echo “this is ${num}nd”

esc :x 回车

chmod +x second

./second

输出：

this is            //以为找不到numnd这个变量

this is 2 nd        //不用解释了吧

this is {2}nd       //错误用法

this is 2nd      //${num}与$num效果相同，拼字符串可以用前者