Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!lll-winken!uunet!mcvax!hp4nl!eutrc3!wzv!wietse
From: wietse@wzv.UUCP (Wietse Z. Venema)
Newsgroups: comp.unix.wizards
Subject: Re: preserving message boundaries on named pipes - System V
Message-ID: <296@wzv.UUCP>
Date: 18 May 89 08:01:02 GMT
References: <571@lehi3b15.csee.Lehigh.EDU>
Reply-To: wietse@wzv.UUCP (Wietse Z. Venema)
Organization: Eindhoven University of Technology, The Netherlands
Lines: 15

In article <571@lehi3b15.csee.Lehigh.EDU> murrey@lehi3b15.csee.Lehigh.EDU (Erik Murrey) writes:
>System V.3.1 Unix
>
>Is it possible to preserve message boundaries on named pipes under
>System V?  For instance, if a process sends two separate messages (via
>two write()'s) down a named pipe, how can the receiver read those as
>two separate messages?  

Under UNIX, the reader just reads what the writer wrote into the pipe.
There are no magic cookies between the `data'. What you seem to want
is provided by the message-queue (the msgop(2) facilities.
-- 
work:	wswietse@eutrc3.uucp	| Eindhoven University of Technology
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