Re: command substitution subshell exits when assigning to readonly variable

[Zachary Santer]

On Wed, Oct 18, 2023 at 11:23 AM alex xmb sw ratchev <fxmbsw7@gmail.com>
wrote:

> oh uhm sorry , to tell in short .. it looks for ending ' r ' for readonly
> in declare -p _var_ output
>
Here's a better way to do that:
$ unset var
$ var='word'
$ if [[ ${var@a} == *'r'* ]]; then
>   printf '%s\n' "var is readonly"
> else
>   printf '%s\n' "var isn't readonly"
> fi
var isn't readonly
$ readonly var
$ if [[ ${var@a} == *'r'* ]]; then
>   printf '%s\n' "var is readonly"
> else
>   printf '%s\n' "var isn't readonly"
> fi
var is readonly

>From the manual:
Parameter Expansion
[...]
${parameter@operator}
Parameter transformation. [...]
a
The  expansion  is  a string consisting of flag values representing
parameter's attributes.

Zack