linker error

[kath.neumann]

Hi,

I just started to get a grip on C++ and and went through the tutorial.
However, not even the standard "hello world" exercise works out :( I
do get a linker error "[Linker Error] Unresolved external 'WinMain'
referenced from C:\PROGRAM FILES\BORLAND\C BUILDER5\LIB\C0 W32.OBJ"

my code (Borland C++ builder 5) is as follows:
#include <condefs.h>
#include <iostream.h>
#include <conio.h>
#pragma hdrstop

//---------------------------------------------------------------------------
int main (int argc, char **argv)
{
cout << "Hello World!" << endl;
cout << endl << "press any key to continue...";
getch();
return 0;
}
Any idea?

THANKS!

kath

[Victor Bazarov]

ka**********@we b.de wrote:

I just started to get a grip on C++ and and went through the tutorial.
However, not even the standard "hello world" exercise works out :( I
do get a linker error "[Linker Error] Unresolved external 'WinMain'
referenced from C:\PROGRAM FILES\BORLAND\C BUILDER5\LIB\C0 W32.OBJ"

my code (Borland C++ builder 5) is as follows:
#include <condefs.h>
#include <iostream.h>
#include <conio.h>
#pragma hdrstop

//---------------------------------------------------------------------------
int main (int argc, char **argv)
{
cout << "Hello World!" << endl;
cout << endl << "press any key to continue...";
getch();
return 0;
}
Any idea?

Unfortunately, yes. You're building this as a Windows application.
If so, then your application doesn't start in 'main', it has to start
in 'WinMain', which you don't have and that's what the linker is
complaining about. MS Windows programming is not the same as just
plain programming. That's why you probably want to set aside the
"Windows" side of things for now and switch to creating what is known
as "Console Applications". See appropriate settings described in the
help system for your compiler. Or ask in the newsgroup dedicated to
your compiler (see the 'borland.public .*' hierarchy).

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

[=?ISO-8859-1?Q?Erik_Wikstr=F6m?=]

On 2007-07-23 17:40, ka**********@we b.de wrote:

Hi,

I just started to get a grip on C++ and and went through the tutorial.
However, not even the standard "hello world" exercise works out :( I
do get a linker error "[Linker Error] Unresolved external 'WinMain'
referenced from C:\PROGRAM FILES\BORLAND\C BUILDER5\LIB\C0 W32.OBJ"

my code (Borland C++ builder 5) is as follows:
#include <condefs.h>

Non-standard header, and not used, skip it.

#include <iostream.h>

Old header, nowadays all standard headers are included without the .h
suffix, so it should be just #include <iostream>

#include <conio.h>

Non-standard, it's generally a good idea to stay away from such headers
while learning C++, since it reduces the changes of learning any bad habits.

#pragma hdrstop

Non-standard and I don't know what it does. Keep it if you think it's
useful, but considering the name of the pragma it's probably something
that should be used in header-files.

//---------------------------------------------------------------------------
int main (int argc, char **argv)

Unless you actually parse the command line arguments I would recommend
to use the simpler form: int main().

{
cout << "Hello World!" << endl;

This should give you a compiler error, cout is not defined. Either
include the namespace (std::cout << ...) or put 'using namespace std;'
above the main-function. I prefer the first but that's just me.

cout << endl << "press any key to continue...";

Ditto.

getch();

If used just to prevent the console from closing as soon as the program
is done, I think it's better to use std::cin.get() which will require
you to press enter. If you use this you can get rid of the include for
conio.h also.

return 0;
}
Any idea?

You have probably specified it as a windows GUI program when you created
the project (or whatever Borland calls it), you need to specify it as a
native win32 project.

By the way, it seems to me that Borland C++ Builder 5 is quite old by
now, at least one newer version is out and you might want to consider
upgrading. If cost is an issue there are free alternatives, both Visual
C++ 2005 from MS and DevC++ (which comes with gcc).

--
Erik Wikström

[kath.neumann]

On 23 Jul., 17:55, "Victor Bazarov" <v.Abaza...@com Acast.netwrote:

kath.neum...@we b.de wrote:

I just started to get a grip on C++ and and went through the tutorial.
However, not even the standard "hello world" exercise works out :( I
do get a linker error "[Linker Error] Unresolved external 'WinMain'
referenced from C:\PROGRAM FILES\BORLAND\C BUILDER5\LIB\C0 W32.OBJ"

my code (Borland C++ builder 5) is as follows:

#include <condefs.h>
#include <iostream.h>
#include <conio.h>
#pragma hdrstop

//---------------------------------------------------------------------------
int main (int argc, char **argv)
{
cout << "Hello World!" << endl;
cout << endl << "press any key to continue...";
getch();
return 0;
}

Any idea?

Unfortunately, yes. You're building this as a Windows application.
If so, then your application doesn't start in 'main', it has to start
in 'WinMain', which you don't have and that's what the linker is
complaining about. MS Windows programming is not the same as just
plain programming. That's why you probably want to set aside the
"Windows" side of things for now and switch to creating what is known
as "Console Applications". See appropriate settings described in the
help system for your compiler. Or ask in the newsgroup dedicated to
your compiler (see the 'borland.public .*' hierarchy).

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

Hi Victor,
it is running now, thanks for your help!!! I created it as console
application, that was indeed the reason. thanks for this tip :-)
Cheers,
Kathleen

[BobR]

<ka**********@w eb.dewrote in message...
On 23 Jul., 17:56, Neelesh Bodas <neelesh.bo...@ gmail.comwrote:

>Use some standard-compliant compiler. Typical options are g++(linux),
devc++(windows ), but I am sure there are other options too.

>Hi,
thanks, it is running now :)
thanks for your recommendations on compiler, I'll check that soon!
Cheers, Kathleen

FYI: Dev-C++ is not a compiler, it is an IDE. There is an option to download
a Dev-C++ package that contains the GNU GCC(MinGW) compiler.

Dev-C++ IDE: http://www.bloodshed.net/

--
Bob R
POVrookie
- -
MinGW (GNU compiler): http://www.mingw.org/
MinGWStudio http://www.parinyasoft.com/ (GNU/Linux & window$)
wxWidgets URL: http://www.wxwidgets.org
Code::Blocks http://www.codeblocks.org/

[BobR]

Erik Wikström <Er***********@ telia.comwrote in message...

>
.... or put 'using namespace std;'
above the main-function.

Why not *in* main()?

--
Bob R
POVrookie

[James Kanze]

On Jul 23, 7:02 pm, "Alf P. Steinbach" <[e-mail] wrote:

* Victor Bazarov:

[...]

g++ supports standard "main" by default,
Visual C++ supports standard "main" when using appropriate switches (by
default Visual C++ is also non-standard-conforming wrt. exceptions, RTTI
and for-loop syntax, so it must be browbeaten into submission).

Aren't they all? You need -std=c++98 -pedantic with g++, and
God knows how many options with Sun CC. Add to that the fact
that pure C++ compliance locks you out of a lot of Posix, and
what's a programmer to do?

which you don't have and that's what the linker is
complaining about. MS Windows programming is not the same
as just plain programming. That's why you probably want to
set aside the "Windows" side of things for now and switch to
creating what is known as "Console Applications".

Good advice.

I know this is off topic, but the issue comes up so often: what
the hell is a "console application"? How does it differ from
any other application, other than, perhaps, it doesn't use
certain libraries? (In which case, of course, you don't need to
click anything. Just don't include the appropriate headers, nor
link against the corresponding library.)

Unless I've misunderstood something greatly, in the end, an
application is an application. If it invokes some system
function which opens a window, and plays around in it, then it
is a GUI (or Windowing) application, but that's a result of the
code the programmer wrote, and nothing else. The applications I
write don't normally do this: are they automatically console
applications (even if they are started by a cronjob, or at
system start-up, with cin, cout and cerr connected to
"/dev/null")?

I'd add: use command line tools for building.

Is there any other way? All the IDE's that I know (admittedly,
NOT Visual Studio) do is generate command lines.

An IDE adds too much "helpful" stuff that just gets in the way.

:-) Boy can I agree with you there.

At least for production code. I can imagine that when learning,
"one thing at a time" is not a bad policy, and if you could find
an IDE which actually worked correctly and usefully, it would be
nice. But professionally, never.

--
James Kanze (GABI Software) email:ja******* **@gmail.com
Conseils en informatique orientée objet/
Beratung in objektorientier ter Datenverarbeitu ng
9 place Sémard, 78210 St.-Cyr-l'École, France, [phone]

[James Kanze]

On Jul 23, 5:56 pm, Neelesh Bodas <neelesh.bo...@ gmail.comwrote:

On Jul 23, 8:40 pm, kath.neum...@we b.de wrote:

Use some standard-compliant compiler. Typical options are g++(linux),
devc++(windows) , but I am sure there are other options too.

Watch it. I have no idea what devc++ is, but g++ is not
standards compliant, by a long shot. "g++ -std=c++98 -pedantic"
tries to be, up to a certain point, but even it ignores some
major features of C++ (like export).

--
James Kanze (GABI Software) email:ja******* **@gmail.com
Conseils en informatique orientée objet/
Beratung in objektorientier ter Datenverarbeitu ng
9 place Sémard, 78210 St.-Cyr-l'École, France, [phone]

[Victor Bazarov]

James Kanze wrote:

[..] If I look at my
Windows system, I don't see any difference between applications;
they're all .exe files, regardless of what they do. As far as I
can tell, all of the facilities of the OS are there for all
programs to use, if they want.

If I look at my Windows desktop, they all look like tiny pictures.
As far as I can tell, there are no .exe files.

[..off topic snipped..]

MSDN is your friend (if you really want to know about Windows,
that is). It looks like you were at least curious. Well, don't
you know that there are newsgroups for those discussions? And
here is a link (courtesy of MSDN) answering at least one question
(how to distinguish between a console app and non-console app):
http://support.microsoft.com/kb/90493

V
--
Please remove capital 'A's when replying by e-mail
I do not respond to top-posted replies, please don't ask

[James Kanze]

On Jul 25, 2:36 pm, "Victor Bazarov" <v.Abaza...@com Acast.netwrote:

James Kanze wrote:

[..] If I look at my
Windows system, I don't see any difference between applications;
they're all .exe files, regardless of what they do. As far as I
can tell, all of the facilities of the OS are there for all
programs to use, if they want.

If I look at my Windows desktop, they all look like tiny pictures.
As far as I can tell, there are no .exe files.

Come now. How did those icons get there? Even I know that you
can open a properties dialog, and specify the command for the
program, and I rarely use Windows.

[..off topic snipped..]

MSDN is your friend (if you really want to know about Windows,
that is). It looks like you were at least curious.

All I really wanted was a definition of a term that I'd seen
often enough here, and for which I couldn't figure out any
reasonable meaning. Alf's article filled the bill (and then
some, since I now not only know what was meant, but what I'll
have to do if I ever have to develop applications under
Windows.)

--
James Kanze (GABI Software) email:ja******* **@gmail.com
Conseils en informatique orientée objet/
Beratung in objektorientier ter Datenverarbeitu ng
9 place Sémard, 78210 St.-Cyr-l'École, France, [phone]