Re: variable set in exec'ing shell cannot be unset by child shell

[Chet Ramey]

On 10/15/23 12:24 AM, Martin D Kealey wrote:
> On Sun, 15 Oct 2023, 03:05 Greg Wooledge, <greg@wooledge.org> wrote:
>
> > On Sat, Oct 14, 2023 at 12:55:21PM -0400, Ti Strga wrote:
> > > it's just the "[[ -v foo ]]" tests to see where along the cloning
> > process we are.
> >
> > *Shudder*
>
> Likewise, brrrr.
>
> If the *real* goal is to overwrite a running script with a new version of
> > itself, and then re-exec it, then the correct solution is to wrap the
> > script in a single compound command so that it gets read and parsed up
> > front, before beginning execution of the main loop.  Either wrap the whole
> > thing in "{" ... "}" as Grisha suggested, or wrap the whole thing in a
> > "main()" function and then call main "$@".
>
> Agreed. Either way, don't forget to put "exit;" just before the closing
> "}". Or write « exec main "$@" ».

That's not going to work; `exec' doesn't work with shell functions. It
will exit the shell for you, though.

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/