RE: pws-22: killing the ZSH loops problem

["Andrej Borsenkow" <borsenkow.msk@sni.de>]

> }
> } We need it only if MONITOR is set
>
> Not true!  MONITOR only affects handling of ^Z, not of ^C.  We need to be
> able to properly interrupt such loops in any shell.
>

Ahem ... yes. What about "only in interactive shells?"

> However, we only need it when (a) there's at least one external command
> (you can already interrupt purely builtin loops, try it) and (b) that
> external command doesn't return the proper exit status for zsh to learn
> that it caught a signal.  We can't know (b) in advance, so I can't come
> up with anything useful for (a) except to fork twice on every external
> command, which is horribly wasteful.
>

If don't miss something again: we have to fork only for the loop as whole. In
other words, only if the command being executed (top-level command) is a complex
command. This means, that in following

while xxx
  while yyy
  done
done

we only fork once for the outer loop and only, if it was input to PS1. It means,
we don't need to fork for the loops in functions (because theay are *not* zsh
commands), so, it seems, execution time penalty is acceptable. After all, you
don't use loops on every prompt.

> } And it just occured to me - is it possible to kill/stop/resume shell
> } function?
>
> Yes.  In fact, that was the recommended workaround for several pipe-into-
> a-loop problems before they gradually got fixed:

Well, thanks for reminder. Still, I'd really prefer properly running loops :-)

/andrej