Date: Wed, 10 Feb 2010 19:58:31 +0200 From: Andriy Gapon <avg@icyb.net.ua> To: Garrett Cooper <yanefbsd@gmail.com>, Naveen Gujje <gujjenaveen@gmail.com> Cc: freebsd-hackers@freebsd.org Subject: Re: System() returning ECHILD error on FreeBSD 7.2 Message-ID: <4B72F3C7.7060004@icyb.net.ua> In-Reply-To: <7d6fde3d1002100952g1518bc36r371020260e81a8c3@mail.gmail.com> References: <39c945731002100925i2e466768peac89cdef15463f2@mail.gmail.com> <7d6fde3d1002100952g1518bc36r371020260e81a8c3@mail.gmail.com>
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on 10/02/2010 19:52 Garrett Cooper said the following:
> Isn't this section of the system(3) libcall essentially doing what
> you want, s.t. you'll never be able to get the process status when you
> call waitpid(2)?
>
> do {
> pid = _wait4(savedpid, &pstat, 0, (struct rusage *)0);
> } while (pid == -1 && errno == EINTR);
> break;
>
> You typically get status via wait*(2) when using exec*(2) or via
> the return codes from system(3), not system(3) with wait*(2)...
Exactly. I think that SIGCHLD handler would effectively 'reap' the child and thus
wait*() in system would rightfully return ECHILD (perhaps after doing EINTR
iteration of the loop).
--
Andriy Gapon
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