别名中的引用变量
问题描述：
我想定义一个实时引用环境变量的别名.例如，如何创建别名来回显 N 的值?
I want to define an alias which references an environment variable in real time. For example, how can I make an alias to echo the value of N?
$ N=4
$ alias sayn="echo $N"
$ N=2
$ sayn
4
答
由于您使用双引号定义别名，$N 在定义之前被扩展，而您的别名实际上是 echo 4代码>.
Since you define your alias using double quotes, the $N is expanded before definition and your alias actually is echo 4.
试试这个:
$N=4
$alias sayn='echo $N'
$N=2
$sayn
2