Re: Avoid non-portable signal(SIGCHLD, SIG_IGN)

[Alexandre Julliard]

Joerg Wunsch  writes:
> The Posix way is to use sigaction(), and set the SA_NOCLDWAIT flag
> bit.  This variant is supported under FreeBSD (don't know for the
> other BSDs).  It has the added bonus that unavailability of the
> automatic zombie reaping feature can be detected at compile-time (the
> macro is not defined then).

The fact that the macro exists doesn't mean it works. Most Linux
kernels don't support SA_NOCLDWAIT, even though the symbol may be
defined in the headers. I don't have the Posix standard, but at least
according to the single Unix spec using SIG_IGN is just as standard as
SA_NOCLDWAIT, and a quick grep of the FreeBSD sources seems to
indicate that it should work. Did I miss something?