Re: 4.2 error: processing command substitution within arithmetic operation

[Greg Wooledge]

On Fri, Jun 24, 2011 at 06:18:08PM +0100, Rui Santos wrote:
> Try this script:
> #!/bin/bash
> 
> declare -ax array
> array[$(( $( echo -n 1001 ) - 1001 ))]=1
> 
> this will issue an error: line 6: 1001: command not found

imadev:~$ unset array
imadev:~$ array[$(( $( echo -n 1001 ) - 1001 ))]=1
imadev:~$ unset array
bash: 1001: command not found

And similar... hmm, this is beyond weird.  I have no idea what's happening
here.

But if you want to work around the problem, I would suggest simplifying
things.  For starters, you do not need $((...)) inside an array index
because the [...] already introduce a math context.

So:

imadev:~$ array[$(echo -n 1001) - 1001]=1
imadev:~$ set | grep array=
array=([0]="1")
imadev:~$ unset array

And that assumes you need to keep the command substitution for some
unstated reason.  If you can get rid of that too, that would be even
better.