Messages in this thread | | | Date | Mon, 3 Feb 1997 08:48:00 -0500 (EST) | From | "Richard B. Johnson" <> | Subject | Re: Async IO |
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On 3 Feb 1997, Jurgen Botz wrote:
> In article <vyzraj29l7p.fsf@issan.informatik.uni-dortmund.de>, > Andreas Schwab <schwab@LS5.informatik.uni-dortmund.de> wrote: > >|> signal number 0 is unused > > > >No, it's not. It has a defined meaning (see kill(2)). > > Hmm, my kill(2) manpage (readhat 4.0) doesn't mention anything > about signal number 0. Enlighten us? > > -- > Jurgen Botz "Unix? What's that? Is that like Linux?" > jbotz@reference.com > I read somewhere that ALL negative signal codes are reserved for USER signals. This should mean that only the positive ones need to be defined. You should be able to use any negative signal code you want for user process signaling.
"The signal code 0 is the "null" signal to be sent ONLY by kill()" (whatever that means). If sigsend() is used to send a signal, and the signal type is 0, error checking is performed, but no signal is sent. This can be used to check the validity of the id and id type ..... This from SunSlosh man pages.
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