Path: utzoo!utgpu!watserv1!maytag!xenitec!tirith!ggk
From: ggk@tirith.UUCP (Gregory Kritsch)
Message-ID: <ggk.658869871@tirith.UUCP>
Date: 17 Nov 20 19:24:31 
Newsgroups: comp.sys.amiga.tech
Subject: Re: PIPEs
In-Reply-To: rhialto@cs.kun.nl (Olaf Seibert)
References: <2424@wn1.sci.kun.nl> <6977@sugar.hackercorp.com>

rhialto@cs.kun.nl (Olaf Seibert) writes:
>As I have been peeking though memory, it appears to be some Tripos
>convention that FileHandles may have some buffer attached to them.
>The argument line pointer that a CLI process receives simply points
>into this buffer.

Neato!  That explains something weird thats been happening to me
recently.  I was playing with the Execute() call the other day, and
found that calling

    Execute("",Input(),NULL);

would actually create a new CLI, using the same window, the only strange
bit being getting a double prompt on the first line.  When the user
types ENDCLI, control is returned to my program.  I went on to try

    Execute("dmail -O",Input(),NULL);

which loaded dmail as expected, and when I exited dmail, I again got the
double prompt.

So I made dmail's "!" (run shell) function work using the first form,
and when I tried it, I got a double prompt, and the message about
"Unknown command -O" (ie the argument list for dmail).

So thats what the buffer variables are used for.  Does anyone know where
they're interpreted - within Read() or the filesystem's ACTION_READ
code, or by some magical BCPL thing?

>Of course, none of this is documented in the DOS manual. Nor should it
>be, in my opinion. But just for the curious, would it be possible that,
>when 2.0 has firmly settled, someone reveals the interesting details of
>the Tripos data structures? Only when it would be of no use to anyone to
>actually use the provided information?

Almost none of the technical side of DOS is documented, and that which
is is documented very poorly.  However, there are enough examples
floating around so that if you have an urge to experiemnt, you can
figure things out.

There is a document on BCPL floating around.  I had it two years ago,
but it was destroyed in a hard disk error (I think).  It documents all
of the dos library, including the BCPL functions and how to call them. 
From it, you can explain how some things work in AmigaDOS.

The magazine "Kickstart" (from Europe) also did an article on Tripos
once upon a time (I've dug it up now - issue 4, aug/sep 86.  It appears
to be published by Commodore Electronics Ltd and/or Ariadne Software
Ltd., both of which are probably Europe-based).  Some useful information
there to, not covered anywhere else that I know of. 

>I suspect that there would be some documentation of Tripos, somewhere.
>Could I get a reference? A copy just might be in our local CS library.

Check with the University of Cambridge - thats where it comes from (and
is apparently still in use there).

>Olaf 'Rhialto' Seibert                               rhialto@cs.kun.nl
>How can you be so stupid if you're identical to me? -Robert Silverberg
--
  Gregory Kritsch                          | University of Waterloo
    Fido:  1:221/208.11110  [1:163/109.30] | 1A Computer Engineering
    UUCP:  ggk@tirith.UUCP                 |--------------------------
           ...!watmath!xenitec!tirith!ggk  | Amiga Fanatic