echo 1. echo "It is $num" 等价于 echo It is $num 且$num为变量的值。 2. echo 'It is $num' 则代表了"It is $num"这个字符串。 来源：CSDN作者：Chernyang链接：https://blog.csdn.net/qq_42890800/article/details/104117558 标签 shell num echo bash shell脚本
