Re: ERR_RETURN doc

[Bart Schaefer <schaefer@brasslantern.com>]

On Sat, Dec 10, 2022 at 6:12 AM Philippe Altherr
<philippe.altherr@gmail.com> wrote:
>
> POSIX' "set -e" specification. That specification is quite a bit longer. Should Zsh's specification repeat all of that? Or should it link to it?

The zsh manual is not rigorously enough written to be treated as a
"specification" and would become even less readable than Ray already
accuses it of being if we tried.  I'd prefer to give a summary and
then reference the POSIX spec for details (but not via URL-link to it;
URLs tend to get stale).

Aside, Martijn Dekker raised a related question back in workers/43874
-- according to the POSIX chapter on Utilities
(https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_08_01)
there are a bunch of circumstances where a non-interactive shell is
required to exit "as if the exit builtin were called".  With ERR_EXIT,
interactive shells are also required to exit in those circumstances.
I'm pretty sure, though haven't re-tested, that zsh does not in fact
exit in some of those (such as a redirection error with a special
builtin) and in some of the cases where it does exit, it does not run
the SIGEXIT trap as implied by "as if the exit builtin" (that being
the actual reason for Martijn's message).

And yes, I used a URL that might become stale, in this message.
Nobody is ever going to need or to be able to go through the archives
and fix that, whereas documentation would be expected to be kept up to
date, a burden I don't wish to impose.