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From: mouse@mcgill-vision.UUCP (der Mouse)
Newsgroups: net.micro.68k
Subject: Re: Re: Holy Holistic, Batman!  (OS-9 and the art of being holistic)
Message-ID: <322@mcgill-vision.UUCP>
Date: Sat, 19-Oct-85 19:37:04 EDT
Article-I.D.: mcgill-v.322
Posted: Sat Oct 19 19:37:04 1985
Date-Received: Wed, 23-Oct-85 06:06:08 EDT
References: <576@sftig.UUCP> <1001@bnl44.UUCP> <11467@rochester.UUCP> <6014@utzoo.UUCP>, <139@mcrware.UUCP>
Organization: McGill University, Montreal
Lines: 69

> > > .... Opening a named pipe is done through open()...
> > That's how it works in Unix too.
> > > ... you read and write from it with no special features like sockets...
> > Same comment.  Sockets are a Berkleyism, and arguably a botch.
> Ok, some of you UNIX-sheltered programmers need a lesson on advanced OS-9
> programming topics.  OS-9 pipes can be "named" much like disk directory
> files:
>
>	open("/pipe/msg_socket", ...)
>
> Any process can open this pipe by name.  The process need not have a common
> ancestor with the creating process creating the pipe.  Another feature of

     Well, under 4.2, you can get this effect with AF_UNIX sockets.  The
(syscall-level)  interface  is  not  as  nice, but  that's what  library
routines are for, and the  UNIX philosophy is (among other things)  that
the  kernel  should contain a MINIMUM amount of code.  Yes, yes, I know,
tell that to Berserkeley (1Mb kernel is it now?).

> ancestor with the creating process creating the pipe.  Another feature of
> the named pipes is that the pipe file manager makes the opened named pipes
> look like disk directories.  For example, the command:
>	copy *.c -w=/pipe/files
> copies all files (*.c) into the pipe named "files".  A subsequent:
> 	dir /pipe/files
> will display the names of the pseudo-files waiting in the pipe.  As the files
> are read, the pseudo files are removed from the pipe.  The files are read in
> FIFO order from the pipe.

     Neat, a pseudo filesystem  in  a pipe.  Hang on while  I write that
for UNIX....  Just a  minute now -  can you access  any file in the pipe
randomly, seek within it, etc?  Or just read them in order?

> > [ .... ]
> The UNIX-style fork REQUIRES memory management to clone the data and stack
> area for the new process.  If this were done without memory management,
> pointers would change causing the forked process to crash.

     So tell me, how do pdp11s run UNIX?

> [ ... ]

> > things that look strange do make sense if you look at them closely and
> > understand what they are used for.  (For example, the fork/exec split looks
> > odd until you try to figure out how to implement things like i/o redirection
> > and shell pipes without it; the ability to modify the environment after
> > the fork but before the exec is important.)
> Must not be too hard to do.  OS-9 does it quite well.  And much faster!

     I always knew there was a reason vfork() existed! :-)

> > Before attempting to "fix Unix's mistakes", it is wise to understand
> > which of them aren't mistakes.
> ...but kludges in disguise!

     Yes, but  there ARE some nice features, not mistakes,  not  kludges
even.  Like  the  all-commands-are-just-programs idea (though the latest
csh  has let's see now, about 50 or so builtin commands; I guess we must
conclude that nothing is ever quite perfect).

     Shall we move to net.religion.computers?  Or maybe net.unix?
-- 
					der Mouse

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