C++ ofstream multifile in Linux

[everlast]

Must i use the MAKE utility in linux bash to build multifile projects?

I tried to write the usual .h and .cpp files that hold the definition and recspectively the declaration of a function, I included the .h file in my main.cpp and called the function within main. when I used g++ to compile main.cpp there was an error: "undefined reference to fun(int)"

Can one use g++ to build multifile projects? Can anyone tell me how to use make, or where to find the best tutorial for it?

Thank You!

[mac11]

Must i use the MAKE utility in linux bash to build multifile projects?

I tried to write the usual .h and .cpp files that hold the definition and recspectively the declaration of a function, I included the .h file in my main.cpp and called the function within main. when I used g++ to compile main.cpp there was an error: "undefined reference to fun(int)"

Can one use g++ to build multifile projects? Can anyone tell me how to use make, or where to find the best tutorial for it?

Thank You!

You dont have to use make, but people usually like to when they start getting lots of files.

Do you have more than 1 .cpp file? If so you have to compile all of them, not just main.cpp (i.e. g++ file1.cpp file2.cpp main.cpp -o myprogram)

I like this site for make reference
http://www.delorie.com/gnu/docs/make/make_toc.html

[everlast]

You dont have to use make, but people usually like to when they start getting lots of files.

Do you have more than 1 .cpp file? If so you have to compile all of them, not just main.cpp (i.e. g++ file1.cpp file2.cpp main.cpp -o myprogram)

I like this site for make reference
http://www.delorie.com/gnu/docs/make/make_toc.html

first: THANK YOU

I've tried g++, and it worked. BUT, the problem was in the code. Why can't I use ofstream class objects (or pointers) as arguments in functions in header files? i.e:

#ifndef MYHEAD_H
#define MYHEAD_H

void myFun (ofstream* );

#endif

I'll look up the link for make anyway, that seems usefull : alot of people seem to be using it (my Bsc mentor as well :) )

[mac11]

Why can't I use ofstream class objects (or pointers) as arguments in functions in header files? i.e:

#ifndef MYHEAD_H
#define MYHEAD_H

void myFun (ofstream* );

#endif

Maybe you figured out your problem already, it's been a while. In case you haven't... you can pass streams around - they're objects. Here is a few samples to show you how to make it go:


main.cpp:

#include <iostream>
#include "testofstream.h"
 
using namespace std;
 
int main () 
{
 
  ofstream outfile;
  outfile.open ("test.txt");
  if (outfile.is_open())
  {
      go( outfile );
      outfile.close();
  }
  else
  {
      cout << "Error opening file";
  }
  return 0;
}
 

testofstream.h:

#ifndef TESTOFSTREAM_H
#define TESTOFSTREAM_H
 
#include <fstream>
 
using namespace std;
 
void go( ofstream &outfile );
 
#endif
 

testofstream.cp p:

#include "testofstream.h"
 
void go( ofstream &outfile )
{
    outfile << "Did this work?" << endl;
}
 

compile with the command

g++ main.cpp testofstream.cpp -o testofstream

and when you run it you should find a file "test.txt" has been created.

[everlast]

Maybe you figured out your problem already, it's been a while. In case you haven't... you can pass streams around - they're objects. Here is a few samples to show you how to make it go:

thanks! i've figured it out (with help of course). I didn't declare the std namespace in my header, so compiler had no idea what is ofstream. : )