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From: Ivan Pozdeev <vano@mail.mipt.ru>
Newsgroups: gnu.bash.bug
Subject: [IDEA] more granular shell options to fix errexit
Date: Sat, 29 Dec 2018 07:23:57 +0300
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With the recent inherit_errexit , the Bash team seems to have finally=20
bumped into a workable way to fix errexit which has been broken for=20
decades (https://mywiki.wooledge.org/BashFAQ/105).

Instead of trying to invent a replacement shell option for that and hope=20
to get it right on the first try (that errexit failed to), make granular=20
options that would each change a single thing -- and see which of them=20
pass the test of time.

The following suggested options aim to eliminate all cases that still=20
exist, outlined on the above link, where an exit code of a command is=20
swallowed/ignored.

* Do not unset `-e' inside a "checked command": only use the logic in=20
the "The shell does not exit" clause when checking the exit code of the=20
checked command, as a unit.

 =C2=A0=C2=A0 (I would argue that this is the intended POSIX semantic in =
the first=20
place but I guess I'm about 25 years late to the party.)
 =C2=A0=C2=A0 Suggested option name: preserve_errexit

* If a command substitution fails, fail the containing command.=20
Suggested name: cmdsubstfail

* Same for process substitution. Fail the command the same way as a=20
pipeline with pipefail (and either only if pipefail is set, or imply=20
pipefail). Suggested name: prsubstfail

(Probably the same for history expansion. I don't use it so have no=20
opinion here.)

I don't have an opinion if they should be shell options or `shopt'=20
options -- no differences to speak of in my book.

--=20
Regards,
Ivan