Path: utzoo!mnetor!uunet!husc6!bloom-beacon!gatech!mcnc!decvax!decwrl!thundr.dec.com!minow
From: minow@thundr.dec.com (Martin Minow THUNDR::MINOW ML3-5/U26 223-9922)
Newsgroups: comp.lang.c
Subject: re: pow() and exit()
Message-ID: <8801091723.AA28950@decwrl.dec.com>
Date: 9 Jan 88 20:01:00 GMT
Organization: Digital Equipment Corporation
Lines: 56


Commenting on the ongoing Standard discussion, Doug Gwyn asks for
"good syntax for a built-in exponentiation operator."  I don't see
where one is needed.  If <stdarg.h> contains
	#define pow(x,y) _pow(x,y)
the syntax analyser/translator can recognize the _pow() and perform
any in-line operations it deems appropriate.

In his discussion on VMS's need to return different values to the operating
system than on Unix, may I point out that the problem predates VMS --
C compilers were available on several PDP-11 operating systems, including
RSX-11M and RT11, before the development of Vax C.  There were (at least)
three sources for such compilers, including the public-domain Decus C,
first published in 1978.

I have been writing portable C applications for at least 10 years.
To solve the exit() argument problem, I include the following in
my programs:

#ifdef vms
#include		<ssdef.h>
#include		<stsdef.h>
#define	IO_SUCCESS	(SS$_NORMAL | STS$M_INHIB_MSG)
#define	IO_ERROR	SS$_ABORT
#endif
/*
 * Note: IO_SUCCESS and IO_ERROR are defined in the Decus C stdio.h file
 */
#ifndef	IO_SUCCESS
#define	IO_SUCCESS	0
#endif
#ifndef	IO_ERROR
#define	IO_ERROR	1
#endif

When I revise the Decus C toolkit to adapt it to the Ansi Standard,
fixing exit() values will be the least of my worries.

From Doug's posting:

>>This is apt, since VMS caused the problem in the first place.
 
>Actually, I agree with this, but since we found a solution that the
>VMS folk could live with, why not stick with it.

I would claim that the problem was caused, not by a specific operating
system, but by people who put constant values into their programs.
Kernighan and Plauger (A Manual of Programming Style) warned
against this *many* years ago.  That the developers of Unix didn't
heed their collegues' warnings doesn't make them less relevant.

Martin Minow
minow%thundr.dec@decwrl.dec.com
decvax!decwrl!dec-rhea!dec-thundr!minow

The above does not reflect the position of Digital Equipment Corp.