Re: why are pipeline commands (allowed to be) executed in subshells?

[Chet Ramey]

On 12/21/22 5:46 PM, Philippe Cerfon wrote:
> Hey Chet.
>
> On Wed, Dec 21, 2022 at 4:20 PM Chet Ramey <chet.ramey@case.edu> wrote:
> > When the shell is running a loop and a child process dies due to SIGINT,
> > the shell pretends it got the SIGINT to break the loop. This reduces user
> > surprise and frustration.
>
> Ah, and I guess it learns about the process being killed by an INT via the CHLD.
>
> Is this somewhere documented? Because I've had read in the "Signals"
> section of the manpage and from there I wouldn't have deduced this.

No, it's how people expect things to work. It looks like I made that change
(break loop when SIGINT trapped) back in May, 2015 from a bug report in
January, 2015. This was to make it have the same loop-breaking behavior as
when SIGINT was not trapped, which had been in bash since bash-2.0 (release
frozen exactly 26 years ago today), so it's been that way for years.

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/