Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!rochester!uhura.cc.rochester.edu!ur-valhalla!micropen!dave
From: dave@micropen (David F. Carlson)
Newsgroups: comp.unix.wizards
Subject: Re: preserving message boundaries on named pipes - System V
Summary: inefficient but would succeed
Message-ID: <719@micropen>
Date: 19 May 89 19:48:32 GMT
References: <571@lehi3b15.csee.Lehigh.EDU> <296@wzv.UUCP>
Organization: Micropen Dirent Writing Systems, Pittsford, NY
Lines: 18

> 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?  
 
Although inefficient and contrived, if limits.h has PIPE_BUF == PIPE_MAX
and the reader and writer used *ONLY* that length, each read would
be an atomic message with no magic cookies required.


-- 
David F. Carlson, Micropen, Inc.
micropen!dave@ee.rochester.edu

"The faster I go, the behinder I get." --Lewis Carroll