采用可变间接扩张猛砸阵列扩展 [英] Bash array expansion using variable indirection expansion

问题描述

我试图扩大数组通过间接扩展我得到的所有值：

I am trying to expand all values in an array I get to through indirect expansion:

> my_array=(coconut banana)
> echo "${my_array[@]}" 
coconut banana
> my_array_name=my_array
> echo ${!my_array_name}
coconut
> echo "${!my_array_name[@]}"
0

我错误地使用数组键的列表中的最后一个命令，因为我不知道如何键入正确的命令？

I am erroneously using "List of array keys" in the last command because I don't know how to type the right command?

我想获得：

coconut banana

可能不诉诸有些难看评估黑客..实例一吸黑客：

possibly without resorting to some ugly eval hack.. Example of one suck hack:

> echo \${$my_array_name[@]}
${my_array[@]}
> eval echo \${$my_array_name[@]}
coconut banana

注意

my_array 可能包含空格的值！

在我写的功能，my_array_name是通过$ 1设置，所以我不能使用，从字面上。

In the function I am writing, my_array_name is set through "$1" so I cannot use that literally.

类似于：<一href=\"http://unix.stackexchange.com/questions/20171/indirect-return-of-all-elements-in-an-array\">http://unix.stackexchange.com/questions/20171/indirect-return-of-all-elements-in-an-array但我需要避免使用评估从讨厌的影响，如果环境被黑客的剧本将有保障的只是在正确的时间的。 ..

Similar to: http://unix.stackexchange.com/questions/20171/indirect-return-of-all-elements-in-an-array but I need to avoid using eval to protect from the nasty effects the script would have if the environment was "hacked" just at the right time...

推荐答案

这应该工作

my_array_name='my_array[@]'
echo "${!my_array_name}"

评论后：你要创建阵列和名称的字符串[@]'，另一个例子

After comment : you have to create a string with the name of the array and '[@]', another example

my_array_name="$1"'[@]'
echo "${!my_array_name}"

注释之后：测试在一个函数

After comment : test in a function

display_elem() {
  local arrname
  arrname="$1[@]"
  printf "%s\n" "${!arrname}"
}

display_elem my_array

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