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

[Greg Wooledge]

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*

I foresee so much more pain in your future.  Seriously, this is going
to blow up in your face at some point.  -v peeks into some incredibly
dark and spooky corners of the shell, and will expose *precisely* how
your assumptions about the shell differ with those of the bash author.
Also, it's been historically buggy.

I'm inclined to agree with Grisha Levit.  This whole thing looks like
a massively out-of-control X-Y problem.  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 "$@".  That way, you can overwrite the file
without sabotaging running instances of the script.