Re: read-only flag is lost for functions in sub shells

[Chris F.A. Johnson]

On Thu, 31 Jul 2014, Chet Ramey wrote:
> On 7/31/14, 10:51 AM, Linda Walsh wrote:
...
> > I thought the idea of RO vars being passed to children was considered
> > desirable?
>
> As Greg says, there's no existing mechanism to do that using the
> environment, which is the only way to communicate across exec(2).  I
> could invent something, but what would be the point?

  It's not hard to do, e.g. as a comma-separated list of readonly
  variables:

export READONLY_VARS=foo,bar,why,not foo bar why not

  In the receiving script:

if [[ -n $READONLY_VARS ]]
then
  IFS=, read -a rov <<< "$READONLY_VARS"
  readonly "${rov[@]}"
fi
foo=q ## not permitted

--
Chris F.A. Johnson, <http://cfajohnson.com>