Re: gawk: sigpipe1.awk:7: fatal: print to "yes | true" failed: Broken pipe

[arnold]

> >> On Dez 12 2023, arnold@skeeve.com wrote:
> >>
> >> > It's inherently racy; the SIGPIPE handling is done around calls
> >> > to stdio's popen(), which does fork+exec.  I just took a look at
> >> > the code and I don't see that there is anything else I can do.
> >>
> >> You could just use an empty signal handler, which is not inherited
> >> across exec.
> >
> > I don't understand what you mean. Can you show me some code?
>
> void ignore_sigpipe (int sig) { }

Hmmm.... Gawk runs with signal(SIGPIPE, SIG_IGN), resetting to
SIG_DFL right before popen() and then back to SIG_IGN afterwards,
relying on EPIPE instead to detect errors.

If I put the above into place before the popen() and then go
back to SIG_IGN afterwards, that hopefully cloes the window
where a SIGPIPE could arrive and do damage.

At least, I think that's how I understand what would be going on.

I will make a change like that and see if anything breaks, and
if not I'll post a patch for review.

Thanks,

Arnold