linux中$与()的一点使用疑惑解释

a=$(cat 1.sh)
等价于
a=`cat 1.sh`


a=(cat 1.sh) 相当于定义一个a数组,内容为cat 1.sh
a=(`cat 1.sh`)相当于把1.sh里面的内容当成a的数组,a仍旧是一个数组
a=$(`cat 1.sh`)此命令会报错,不能执行

 

[root@zejin240 chenzejin]# cat 1.sh 
hello world 2016
better
[root@zejin240 chenzejin]# a=(cat 1.sh) [root@zejin240 chenzejin]# b=(`cat 1.sh`) [root@zejin240 chenzejin]# c=$(cat 1.sh) [root@zejin240 chenzejin]# d=`cat 1.sh`

[root@zejin240 chenzejin]# echo ${a[@]} cat 1.sh [root@zejin240 chenzejin]# echo ${b[@]} hello world 2016 better [root@zejin240 chenzejin]# echo ${c[@]} hello world 2016 better [root@zejin240 chenzejin]# echo ${d[@]} hello world 2016 better
[root@zejin240 chenzejin]#
echo $a cat [root@zejin240 chenzejin]# echo $b hello [root@zejin240 chenzejin]# echo $c hello world 2016 better [root@zejin240 chenzejin]# echo $d hello world 2016 better

[root@zejin240 chenzejin]# e=$(`cat 1.sh`)
-bash: hello: command not found
posted @ 2016-01-15 08:58  泽锦  阅读(347)  评论(0编辑  收藏  举报