how can I index an array by it's name in bash

Question

I have such bash code below, I just want to know how to find an array by it's name:

#!/bin/bash

arr=("object1" "object2")

name="arr"

array=${!name}
echo object0 = ${array[0]}
echo object1 = ${array[1]}

outputs below:

object0 = object1
object1 =

I'm wondering why I cannot index the second element and how can I do that!!!

You fail to get the second element because $arr when arr is an array yields the zeroth element of the array (only). So the assignment array=${!name} assigns a single value to array, and then you can't pick up multiple values from it. — Jonathan Leffler
– Jonathan Leffler, Commented May 8, 2015 at 5:47
Thank you, I googled it, and now I understand what does '@' mean! — 楚狂人
– 楚狂人, Commented May 8, 2015 at 6:35

anishsane · Accepted Answer · 2015-05-08 05:31:48Z

3

Use this syntax:

name="arr[@]"
array=("${!name}")

Your other code is fine.

Or if you have this passed as a variable, name="arr"

You can always use this hack:

name_temp="$name[@]"
array=("${!name_temp}")

answered May 8, 2015 at 5:31

anishsane

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1 Comment

Thanks, this really solve my problem, yeah, I have the output that I expected!