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Groups > gnu.bash.bug > #15672

Re: set -e ignored in subshell if part of command list

From achurch@achurch.org (Andrew Church)
Newsgroups gnu.bash.bug
Subject Re: set -e ignored in subshell if part of command list
Date 2019-11-14 00:59 +0900
Message-ID <mailman.1349.1573660804.13325.bug-bash@gnu.org> (permalink)
References <13040a55-507d-e072-e827-be7c33be968f@case.edu> <5dcc2873.17477@msgid.achurch.org>

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>"The -e setting shall be ignored when executing the compound list following
>the while, until, if, or elif reserved word, a pipeline beginning with the
>! reserved word, or any command of an AND-OR list other than the last."
>
>(from 
>https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_25_03)
>
>The subshell inherits this state (being part of an and-or list) from its
>parent.

Is that really the intent of the requirement, though?  The same section
states: "This requirement applies to the shell environment and each
subshell environment separately", which I read to mean that the rules
should be evaluated without consideration of any parent or subshell
environment other than the one in which the -e option is being applied.
And the example:

set -e; (false; echo one) | cat; echo two

shows rule 1 ("The failure of any individual command in a multi-command
pipeline shall not cause the shell to exit") not being applied within
the subshell, even though the subshell as a whole is an "individual
command in a multi-command pipeline".  I don't see any suggestion that
the case of an AND-OR list in rule 2 should be treated differently, and
absent an explicit requirement one way or the other, I think the
expected behavior here would be that the behavior of the subshell is
independent of the subshell's context in the parent shell.

  --Andrew Church
    http://achurch.org/

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Re: set -e ignored in subshell if part of command list achurch@achurch.org (Andrew Church) - 2019-11-14 00:59 +0900

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