Multifile Programming

I am doing a multifile program. There are two files first.cpp and second.cpp that I would like to include in the main file main.cpp. I have first.h and second.h, that I include using

Code:

// in file main.cpp
#include "first.h"
#include "second.h"

The .h files look something like this:

Code:

// in files first.h and second.h
#ifndef __FIRST_H
#define __SECOND_H

int	init(void);

#endif

And in the files first.cpp and second.cpp, I have added the lines

Code:

// in files first.cpp and second.cpp
#include "first.h"
#include "second.h"

I use the Turbo C++ 3.0 compiler. I have set the include directory to the directory that contains the .h and .cpp files. I can compile successfully, but I can't link it. The error message is 'Undefined symbol init() in module main.cpp'. Please help.

Put your header files into the directory you are compiling from.

first.h:

Code:

#ifndef FIRST_H
#define FIRST_H
void first(void);
#endif // FIRST_H

second.h:

Code:

#ifndef SECOND_H
#define SECOND_H
void second(void);
#endif // SECOND_HS

main.h:

Code:

#ifndef MAIN_H
#define MAIN_H
#include "first.h"
#include "second.h"
#endif //MAIN_H

first.cpp:

Code:

#include "first.h"
#include <iostream>
void first(void)
{
 std::cout << "First" << std::endl;
}

second.cpp

Code:

#include "second.h"
#include <iostream>
void second(void)
{
 std::cout << "Second" << std::endl;
}

main.cpp

Code:

#include "main.h"
int main()
{
 first();
 second();
}

First, compile first.cpp and second.cpp.

Then compile main.cpp, passing first.o and second.o as additional arguments to the command line (read your compiler's documentation for details on how the command line input should be formatted).

That's basically it.

Thanks a lot, Sebastiani! Your solution saved me. Thanks goes to Lurker also.