Re: use of set -e inside parenthesis and conditionnal second command

[Ilkka Virta]

On Tue, Nov 17, 2020 at 4:07 PM Pierre Colombier via Bug reports for the
GNU Bourne Again SHell <bug-bash@gnu.org> wrote:

> #2
> pierre@zebulon: ~ $ (set -e ; echo A ; false ; echo B ) && echo C.$?
> #3
> pierre@zebulon: ~ $ bash -c 'set -e ; echo A ; false ; echo B ' && echo
> C.$?



     If it's not a bug, I think the manual should explain the difference
> between #2 and #3 in section 3.2.3 and 3.2.4.3
>

Technically, I suppose the description of set -e already says that (4.3.1
The Set Builtin):

"If a compound command or shell function executes in a context where -e is
being ignored,
none of the commands executed within the compound command or function body
will be affected
by the -e setting, even if -e is set and a command returns a failure
status. "

The subshell (set -e; echo...) is a compound command, and it executes as a
non-final part of the && list,
so none of the commands within are affected by set -e. The other command
explicitly invoking bash is not
a subshell or any other type of compound command.

Now, perhaps that could use a note explicitly saying this also means
subshells, even though they may
have set -e in effect independently of the main shell.

The part explaining subshells (3.7.3 Command Execution Environment) could
perhaps also use a mention
of that caveat, since it does mention set -e already, though in the context
of command substitution.

https://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html
https://www.gnu.org/software/bash/manual/html_node/Command-Execution-Environment.html