Re: Whaddaya think?

From	Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups	comp.lang.c
Subject	Re: Whaddaya think?
Date	2024-06-18 02:57 -0700
Organization	None to speak of
Message-ID	<87v826zi87.fsf@nosuchdomain.example.com> (permalink)
References	(10 earlier) <v4oi9f$gnf3$1@dont-email.me> <877ceo2iqq.fsf@nosuchdomain.example.com> <v4onrg$hmc2$1@dont-email.me> <v4pe9e$lpi6$1@dont-email.me> <v4r4qg$16pi5$1@dont-email.me>

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Janis Papanagnou <janis_papanagnou+ng@hotmail.com> writes:
> On 17.06.2024 15:38, James Kuyper wrote:
>> On 6/17/24 03:16, Janis Papanagnou wrote:
>>> On 17.06.2024 08:20, Keith Thompson wrote:
>>>> Janis Papanagnou <janis_papanagnou+ng@hotmail.com> writes:
>>>>> If I want a defined exit status (which is what I usually
>>>>> want) I specify 'int main (...)' and provide an explicit
>>>>> return statement (or exit() call).
>>>>
>>>> Why would you ever not want a defined exit status, given that it's
>>>> easier to have one than not to have one? 
>>>
>>> Aren't we agreeing here? (The only difference is that you are
>>> formulating in a negated form where I positively said the same.)
>> 
>> You implied, by saying "If I want a defined exit status", that there are
>> occasions where you don't want a defined exit status
>
> ...where I don't _need_ one. Yes.
> E.g. in code like  main() { printf("hello, world\n"); }

That's been a syntax error since C99, which dropped the "implicit
int" rule.  (Some compilers accept it by default to cater to old
code, if you don't ask them to enforce the current language rules.)

>> - and he's
>> questioning that. Things that are undefined are seldom useful.
>
> I disagree. If things are undefined it _may_ just not matter.
> If things matter they should not (ideally never) be undefined.

But you have to go out of your way to make it undefined, by
violating the rules of the language.  Why would you do that?
Sheer stubbornness?

In C90 and earlier, falling off the end of main caused an unspecified
exit value, which seems to be what you want for some reason.
In C99 and later, there is no valid way to do that.

<https://www.open-std.org/jtc1/sc22/wg14/www/docs/n1570.pdf>
is a draft of the 2011 ISO C standard.  Section 5.1.2.2.1,
"Program startup", covers what we've been discussing about main.
One more thing to know is that if a requirement uses the word
"shall" outside a constraint (such as the "shall" in paragraph 1),
violating that requirement causes undefined behavior.

You've gotten the idea, based on a badly out of date book, that C
gives you a way to leave the exit status unspecified.  It doesn't.

[...]

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

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Whaddaya think? DFS <nospam@dfs.com> - 2024-06-15 15:36 -0400
  Re: Whaddaya think? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-06-15 22:33 +0100
  Re: Whaddaya think? Ben Bacarisse <ben@bsb.me.uk> - 2024-06-15 23:03 +0100
    Re: Whaddaya think? bart <bc@freeuk.com> - 2024-06-16 00:22 +0100
      Re: Whaddaya think? Ben Bacarisse <ben@bsb.me.uk> - 2024-06-16 10:30 +0100
    Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-16 11:52 -0400
      Re: Whaddaya think? Ben Bacarisse <ben@bsb.me.uk> - 2024-06-17 00:17 +0100
        Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 08:49 -0400
  Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-15 15:22 -0700
    Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-16 12:20 -0400
      Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-16 13:54 -0700
      Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-16 22:41 -0400
        Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-16 22:45 -0700
        Re: Whaddaya think? Kaz Kylheku <643-408-1753@kylheku.com> - 2024-06-17 07:39 +0000
          Re: Whaddaya think? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-06-17 01:22 -0700
          Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 09:50 -0400
            Re: Whaddaya think? Richard Harnden <richard.nospam@gmail.invalid> - 2024-06-17 16:23 +0100
              Re: Whaddaya think? David Brown <david.brown@hesbynett.no> - 2024-06-17 18:46 +0200
              Re: Whaddaya think? Kaz Kylheku <643-408-1753@kylheku.com> - 2024-06-22 22:14 +0000
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-22 17:10 -0700
                Re: Whaddaya think? Phil Carmody <pc+usenet@asdf.org> - 2024-06-23 11:20 +0300
          Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 00:19 -0700
            Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 03:10 -0700
              Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 17:24 -0700
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 17:55 -0700
                Re: Whaddaya think? Kaz Kylheku <643-408-1753@kylheku.com> - 2024-06-19 01:58 +0000
        Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 08:50 -0400
          Re: Whaddaya think? Ben Bacarisse <ben@bsb.me.uk> - 2024-06-17 15:41 +0100
            Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-18 08:12 +0200
              Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 03:07 -0700
      Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-17 00:30 -0400
  Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-16 01:56 +0300
    Re: Whaddaya think? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-06-16 03:26 +0000
      Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 05:41 +0200
        Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-15 21:17 -0700
          Re: Whaddaya think? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-06-16 04:41 +0000
          Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 06:44 +0200
            Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-16 11:09 -0400
              Re: Whaddaya think? David Brown <david.brown@hesbynett.no> - 2024-06-16 17:56 +0200
                Re: Whaddaya think? bart <bc@freeuk.com> - 2024-06-16 18:14 +0100
                Re: Whaddaya think? David Brown <david.brown@hesbynett.no> - 2024-06-17 14:44 +0200
                Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 09:52 -0400
        Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 06:51 +0200
          Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-15 22:21 -0700
            Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 07:41 +0200
              Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-15 22:49 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 11:29 +0200
                Re: Whaddaya think? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-06-16 16:04 +0100
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 17:13 +0200
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-16 13:32 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 07:41 +0200
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-16 23:20 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 09:16 +0200
                Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-17 09:38 -0400
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-17 16:17 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-18 07:09 +0200
                Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-18 03:25 -0400
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 02:57 -0700
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-17 16:15 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-18 08:02 +0200
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-18 19:07 -0700
                Re: Whaddaya think? David Brown <david.brown@hesbynett.no> - 2024-06-19 09:50 +0200
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-19 13:13 -0700
                Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-17 02:21 -0400
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 09:22 +0200
              Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-16 11:11 +0300
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 11:07 +0200
                Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-16 12:38 +0300
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 12:03 +0200
                Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-16 14:31 +0300
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 17:37 +0200
                Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-17 00:45 +0300
              Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-16 17:06 -0700
                Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-16 22:40 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 07:52 +0200
                Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 09:45 -0400
                Re: Whaddaya think? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-06-17 13:16 -0700
                Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-17 17:07 -0400
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-17 15:48 -0700
                Re: Whaddaya think? scott@slp53.sl.home (Scott Lurndal) - 2024-06-17 22:48 +0000
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-17 15:44 -0700
                Re: Whaddaya think? David Brown <david.brown@hesbynett.no> - 2024-06-18 15:00 +0200
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-18 06:57 +0200
                Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 00:25 -0700
                Re: Whaddaya think? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-06-17 02:38 -0400
                Re: Whaddaya think? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-06-18 17:01 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 07:48 +0200
                Re: Whaddaya think? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-06-16 23:29 -0700
                Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-17 09:35 +0200
        Re: Whaddaya think? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-06-16 08:19 +0100
        Re: Whaddaya think? Michael S <already5chosen@yahoo.com> - 2024-06-16 10:44 +0300
          Re: Whaddaya think? Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-06-16 11:13 +0200
    Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-16 11:03 -0400
  Re: Whaddaya think? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2024-06-16 15:52 +0000
    Re: Whaddaya think? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2024-06-16 17:17 +0100
    Re: Whaddaya think? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-06-18 08:06 +0000
    Re: Whaddaya think? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2024-06-25 17:37 +0000
      Re: Whaddaya think? DFS <nospam@dfs.com> - 2024-06-25 14:09 -0400
        Re: Whaddaya think? Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2024-06-25 18:11 +0000

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