Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!wuarchive!mit-eddie!uw-beaver!Teknowledge.COM!unix!hplabs!motsj1!mcdchg!ddsw1!olsa99!mje
From: mje@olsa99.UUCP (Mark J Elkins)
Newsgroups: comp.unix.wizards
Subject: Re: Why isn't argv[argc]==(char *)0 ?
Summary: But 'argv[argc] == (char *)0' on  X/OS (Olivetti Unix)
Keywords: X/OS, Olivetti, LSX, coredump
Message-ID: <8@olsa99.UUCP>
Date: 14 Dec 89 16:20:30 GMT
References: <547.nlhp3@oracle.nl> <1989Nov16.012439.6405@virtech.uucp> <2673@auspex.auspex.com>
Organization: Olivetti Africa
Lines: 57

In article <2673@auspex.auspex.com>, guy@auspex.auspex.com (Guy Harris) writes:
Guy >>>(I.e., unless you have to deal with an archaic UNIX or a Mutant UNIX
Guy >>>From Hell, you can count on argv[argc] == 0.)

In article <1635@ctisbv.cti-software.nl> Pim Zandgerger wrote...
Pim >>In X/OS, a SYSV/BSD hybrid operating system for the Olivetti LSX
Pim >>minicomputers, a reference to argv[argc] will make your program dump core.

> If you mean "a *de*reference *of* 'argv[argc]' will make your program
> dump core", that's true on Suns as well, and some other machines, since
> they don't let you dereference null pointers.
> 
> If you mean "even trying to copy the (pointer) *value* somewhere else
> causes a core dump", then I think the label "Mutant UNIX From Hell" is
> well-deserved; I've nothing against, say, array bounds-checking, but
> "argv" has "argc+1" elements, not "argc" elements - if Olivetti intends
> to get POSIX or ANSI C support on the LSX, they'd better fix this....

Mark Elkins writes....

OK Guys - I am the support person for Olivetti Africa and was a little
upset about the accusation. I ran the following program... (Called 'e.c')


main(ac,av)
int ac;
char *av[];
{
char *cp;

printf("Value of av[ac] = %s\n",av[ac]);
cp = av[ac]; printf("Value of cp = %s\n",cp);
while (ac >= 0) printf("Arg %d = %s\n",ac--,*av++);
}

and it produced.....


Value of av[ac] = (null)
Value of cp = (null)
Arg 4 = e
Arg 3 = one
Arg 2 = two
Arg 1 = three
Arg 0 = (null)

The Machine is a LSX 3020 Machine (68020 @ 17 Meg) running X/OS Rel 2.1
(Olivetti's Unix - Bastardisation of Sys V Rel 3.0 and BSD 4.2 - peppered
with Olivetti features)

Go suck eggs  (or maybe upgrade your system)

(Any replies - please mail mje@olsa99 - my news feed is down)
-- 
  .  .     ___. .__       Olivetti Africa, Unix 'Everything-except-sales'
 /| /|       / /__        UUCP: uunet!olsa99!mje (Mark J Elkins)
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