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From: Keith Thompson <kst-u@mib.org>
Newsgroups: comp.lang.c
Subject: Re: error_t proposal
Date: Thu, 05 Sep 2019 15:14:20 -0700
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James Kuyper <jameskuyper@alumni.caltech.edu> writes:
> On 9/5/19 5:31 PM, Keith Thompson wrote:
> ...
>> VMS (VAX is the hardware, which can also run Unix) does the same for the
>> return status of a program -- which is probably part of the reason we
>> have the EXIT_SUCCESS and EXIT_FAILURE macros in <stdlib.h>.  When I
>> worked on VMS, I sometimes ran into C programs that used "return 1;" or
>> "exit(1);" to indicate failure, but that indicates success on VMS.
>> 
>> (But "return 0;" or "exit(0);" is required to return a successful
>> status, even though the OS treats that as a failure code.)
>
> "If the value of status is zero or EXIT_SUCCESS, an
> implementation-defined form of the status _successful termination_ is
> returned." (7.20.4.3p5).
> I don't believe that a status which the OS treats as a failure code
> could qualify as a successful status. On a platform where successful
> statuses are indicated by odd values, exit(0) must return an odd status.
>
> "If the return type of the main function is a type compatible with int,
> a return from the initial call to the main function is equivalent to
> calling the exit function with the value
> returned by the main function as its argument; ..." (5.1.2.2.3p1).
> So the same should also be true of "return 0;" from main().

Yes, I didn't mean to imply otherwise.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Will write code for food.
void Void(void) { Void(); } /* The recursive call of the void */