Re: Local variables overriding global constants

[Chris F.A. Johnson]

On Wed, 3 Apr 2013, Nikolai Kondrashov wrote:

> Hi everyone,
>
> It seems Bash 4.2.37 doesn't allow functions to redefine global constants
> locally, yet it allows redefining constants local to calling functions.
> Is this as supposed to be, or is it a bug?
>
> I.e. this:
>
>    bash -c 'declare -r v; a() { declare -r v; }; a'
>
> Results in:
>
>    bash: line 0: declare: v: readonly variable

   It doesn't work because you are trying to redefine an existing
   readonly variable.

> While this works:
>
>    bash -c 'a() { declare -r v; }; b() { declare -r v; a; }; b'

   It works because both instances are local to a function and don't
   exist outside their own functions.

--
   Chris F.A. Johnson, <http://cfajohnson.com/>
   Author:
   Pro Bash Programming: Scripting the GNU/Linux Shell (2009, Apress)
   Shell Scripting Recipes: A Problem-Solution Approach (2005, Apress)