warning: return type of main is not int

warning: return type of main is not int

[Byeong-ryeol Kim]

 I often met this warning after installing egcs on rh 5.0.
 Is this harmless?
 The typical code is as follows:
....
void main(int argc, char *argv[])
{
    int sock, i;
    
    if ((argc > 1) && (strcmp(argv[1], "-v") == 0))
        printf("%s", version);
    
    sock = i365_probe();
    for (i = 0; i < sock; i++) {
        printf("Socket %d:\n", i);
        dump_sock(i);
    }
}
...

 "Where there is a will, there is a way."  jinbo21@soback.kornet.nm.kr 
                                           kbeyl@kids.kotel.co.kr      
  For the future of you and me!            hitel: jinbo21

Re: warning: return type of main is not int

[Joe Buck]

>  I often met this warning after installing egcs on rh 5.0.
>  Is this harmless?

The C++ language standard says that main returns int.  The compiler
is warning you that what you are typing is not legal C++.

> void main(int argc, char *argv[])

Re: warning: return type of main is not int

[Byeong-ryeol Kim]

On Fri, 16 Jan 1998, Joe Buck wrote:
...
> The C++ language standard says that main returns int.  The compiler
> is warning you that what you are typing is not legal C++.
> 
> > void main(int argc, char *argv[])
...
 I'm actually a beginner.
 If so, how can I fix it?

 "Where there is a will, there is a way."  jinbo21@soback.kornet.nm.kr 
                                           kbeyl@kids.kotel.co.kr      
  For the future of you and me!            hitel: jinbo21

Re: warning: return type of main is not int

[Joe Buck]

> > The C++ language standard says that main returns int.  The compiler
> > is warning you that what you are typing is not legal C++.
> > 
> > > void main(int argc, char *argv[])
> ...
>  I'm actually a beginner.
>  If so, how can I fix it?

I'll answer this one, but *please* don't use the egcs mailing list to
ask beginner C++ questions.  Try a C++ book or comp.lang.c++.moderated
(I won't advise the unmoderated comp.lang.c++ to anyone).

Just change the "void" to "int".

Re: warning: return type of main is not int

[Joseph H. Buehler]

Byeong-ryeol Kim <jinbo21@soback.kornet.nm.kr> writes:

>  I often met this warning after installing egcs on rh 5.0.
>  Is this harmless?
>  The typical code is as follows:
> ....
> void main(int argc, char *argv[])
> {

That's illegal C/C++, I believe.  The operating system expects an
integer return value from main().

Joe Buehler

Re: warning: return type of main is not int

[Mike Stump]

> Date: Fri, 16 Jan 1998 10:52:41 +0900 (KST)
> From: Byeong-ryeol Kim <jinbo21@soback.kornet.nm.kr>
> To: egcs@cygnus.com

>  I often met this warning after installing egcs on rh 5.0.
>  Is this harmless?
> void main(int argc, char *argv[])

This is reasonably safe, but wrong for C++.  The return type should be
int not void.  Why bother asking us, it takes less time to fix the
code as the compiler instructs.  return 0, if you don't know of a
better value to return.

Re: warning: return type of main is not int

[Alexandre Oliva]

Mike Stump writes:

>> From: Byeong-ryeol Kim <jinbo21@soback.kornet.nm.kr>

>> I often met this warning after installing egcs on rh 5.0.
>> Is this harmless?
>> void main(int argc, char *argv[])

> return 0, if you don't know of a
> better value to return.

In fact, you don't even have to bother about returning anything, since
falling off function `main' is equivalent to returning 0, as defined
in [basic.start.main]/5

-- 
Alexandre Oliva
mailto:oliva@dcc.unicamp.br mailto:aoliva@acm.org
http://www.dcc.unicamp.br/~oliva
Universidade Estadual de Campinas, SP, Brasil