From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ankit Jain <ankitjain1580@yahoo.com>
Subject: Re: variable length function
Date: Wed, 15 Jun 2005 09:36:10 +0100 (BST)
Message-ID: <20050615083610.15622.qmail@web52909.mail.yahoo.com>
References: <6a00c8d50506142333197a5b0@mail.gmail.com>
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To: Steve Graegert <graegerts@gmail.com>, Glynn Clements <glynn@gclements.plus.com>
Cc: linux-c-programming@vger.kernel.org

Hi

thanks for help

Well then i am just trying to clear my concept again.

main()
{

         printf("This is main");

}

now this simple function main according to this
discussion will return a int value.......Am i
right....but is it true with any compiler?

another thing........... if it returns a int value and
we have not returned any value explicitly.........then
what is the value returned ....as far as i know its a
non-zero value. but then what will that mean.....?

regards,

ankit
--- Steve Graegert <graegerts@gmail.com> wrote:

> On 6/15/05, Glynn Clements
> <glynn@gclements.plus.com> wrote:
> > 
> > Steve Graegert wrote:
> > 
> > > > also, if what is the default return type and
> value of
> > > > main function in C in gcc, ansi C and turbo C?
> > 
> > > Question 4:
> > > ISO C99 suggests the return type of main() to be
> of type int.  There
> > > is a never ending debate among some
> professionals whether void is
> > > equally legal.  Some compilers behave like ANSI
> C that allows
> > > declaration of type void but return int
> implicitly.  In other words:
> > > stick to int.
> > 
> > The value returned from main is used as the
> process' exit code. If you
> > declare main() as returning void, and return from
> it, the process is
> > likely to have a random exit code (e.g. whatever
> happens to be in the
> > EAX register upon return from main()).
> 
> Yes, another important issue.  The most reliable way
> to return a valid
> and correct value I am aware of is returning a value
> explicitly. 
> You're right. just declaring int does not imply the
> return code to be
> the expected one, though being valid.  It is __not__
> guaranteed that
> the return type is not some random integer value
> unless it is returned
> explicitly.
> 
> Another point that comes to mind are compilers with
> distinct calling
> conventions for int and void functions and job
> control for example. 
> This can cause headaches when main() does not push a
> return value on
> the stack, as being the case with void, and the
> caller tries to pop an
> int which obviously is not found.  It __may__ lead
> to subtle crashes
> later on.
> 
> 
> Kind Regards
> 
>     \Steve
> 
> --
> 
> Steve Graegert <graegerts@gmail.com> ||
> <http://www.technologies.de/~sg/>
> Independent Software Consultant {C/C++ && Java &&
> .NET}
> Mobile: +49 (176)  21 24 88 69
> Office: +49 (9131) 71 26 40 9
> 


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