Path: utzoo!attcan!uunet!mcsun!unido!zgdvda!sherekhan!dingelde
From: dingelde@sherekhan.uucp (Dennis Dingeldein)
Newsgroups: comp.lang.c++
Subject: Again: Access to argc,argv outside main()
Message-ID: <3129@zgdvda.zgdvda.uucp>
Date: 25 Oct 90 14:23:17 GMT
Sender: news@zgdvda.zgdvda.uucp
Organization: ZGDV Darmstadt, FRG
Lines: 76

/* 

Hello again,

This Code refers to my original posting. 
I asked there
	HOW DO I ACCESS ARGC AND ARGV OUTSIDE MAIN ?

I've got only anwers of the
type "You can't do anything before entering main(), main() is the
entry point and first thing ever executed". To show that this is
wrong, I send a small test. This demonstrates calling Methods/Functions
before entering main().

The code shows that global objects are created before main() is
entered. 
So there is still the problem I described originally:

	HOW DO I ACCESS ARGC AND ARGV OUTSIDE MAIN ?

Perhaps there is no solution to this problem. Then, is it due to
my compiler (g++ 1.35.1), due to me, due to C++-Design ?

   The following code was compiled with g++

   It defines a class ("A") and create two objects of this class.

   The first Object ("I_will_be_called_before_main") tries to
   access argc, argv as mentioned by friendly people.
   Of course, this do not print argv[0], because this object
   actually is created *before* entering main.
   But at that time main() is not yet entered, and global_{argc,argv} are
   not yet defined.

   The second Object "I_will_be_called_after_main" is inside main(), 
   and the lines above do
   initialize global_{argc,argv}. So there I get the expected result, i.e.
   argv[0].

*/
   
#include <stdio.h>

int global_argc = 0;
char **global_argv = NULL ;

// a class
class A {
public:
	A();
};

A::A() {
	printf( "argc: %d ", global_argc );
	if (global_argc!=0) 
		printf( "argv[0]: %s", global_argv[0] );
	printf( "\n" );
}

// the test program

// an object - outside main() - creates only zero, no argv
A I_will_be_called_before_main ; 

main( int argc, char **argv ) {

	// at first set up argc, argv
	global_argc = argc ;
	global_argv = argv ;
	// an object -  inside main() - creates only 1, and argv[0]
	A I_will_be_called_after_main ; 
}
Dennis Dingeldein	ZGDV Zentrum fuer Graphische Datenverarbeitung
(dingelde@zgdvda.uucp)	Wilhelminenstr. 7 		    wMw
			D-6100 Darmstadt, West Germany	    ~.~
			Phone: +49/6151/155-101		    \-/