Re: [LI] C Programming problem

["Binand Raj S." <binand@xxxxxxxxxxxxxxxxxxxxx>]

SHRIDHAR N. DAITHANKAR forced the electrons to say:
>  Does a C program need to return a value from main? C++ forces it, that's
> OK, but so far I have not experienced any problem for main(){}(i.e.
> without any return parameters). Do I need those return parameters in a C
> program?
> 
>  Bye
>   Shridhar

Yes. It does.
main() works because ANSI C currently assumes a function to by default return
an int. And the empty parameter list also works because ANSI C is compatible
with the old K&R C.

Here is an excerpt from the C FAQ:

  Question 11.12
  
   Can I declare main as void, to shut off these annoying ``main returns
   no value'' messages?
     _________________________________________________________________
   
   No. main must be declared as returning an int, and as taking either
   zero or two arguments, of the appropriate types. If you're calling
   exit() but still getting warnings, you may have to insert a redundant
   return statement (or use some kind of ``not reached'' directive, if
   available).
   
   Declaring a function as void does not merely shut off or rearrange
   warnings: it may also result in a different function call/return
   sequence, incompatible with what the caller (in main's case, the C
   run-time startup code) expects.
   
   (Note that this discussion of main pertains only to ``hosted''
   implementations; none of it applies to ``freestanding''
   implementations, which may not even have main. However, freestanding
   implementations are comparatively rare, and if you're using one, you
   probably know it. If you've never heard of the distinction, you're
   probably using a hosted implementation, and the above rules apply.)
   
   References: ANSI Sec. 2.1.2.2.1, Sec. F.5.1
   ISO Sec. 5.1.2.2.1, Sec. G.5.1
   H&S Sec. 20.1 p. 416
   CT&P Sec. 3.10 pp. 50-51


Binand

-- 
#include <stdio.h>                                   | Binand Raj S.
char *p = "#include <stdio.h>%cchar *p = %c%s%c;     | This is a self-
int main(){printf(p,10,34,p,34,10);return 0;}%c";    | printing program.
int main(){printf(p,10,34,p,34,10);return 0;}        | Try it!!
--------------------------------------------------------------------
The Linux India Mailing List Archives are now available.  Please search
the archive at http://lists.linux-india.org/ before posting your question
to avoid repetition and save bandwidth.