gcc question

platipo · 12-16-2006, 10:13 AM

Hi, I'm quite a newbie, and I have a problem with gcc: I tried to compile a simple hello world like program, I have inluded iostream, and the compiler seems to have no problem with that (if I put iostream.h it warns me that the header is deprecated/antiquated) but it tells me cout isn't defined... how can that happen? Any suggestions?

Nylex · 12-16-2006, 10:14 AM

You use g++ to compile C++ programs. If you're going to use gcc, then you need to link the C++ library, e.g. by using "gcc -lstdc++ hello.c".

Edit: do you also have "using namespace std;" or "using std::cout" in your program?

platipo · 12-16-2006, 10:22 AM

already tried that; g++ gives me just the same problem, I have none of the lines you mentioned in my program, gonna try now

Edit: using namespace std gives me a load of errors and warnings, while using std::cout removes that error and leaves me with only endl undefined

Edit2:tried removing endl, it tells me of lots of undefined references to std::ios_base::init in function _static_inizialization_and_destruction_0
and of more undefined references to std::cout, to std::basic_ostream<char,and to _gxx_personality_v0

Nylex · 12-16-2006, 10:25 AM

If you use the deprecated header, you should still get an executable file. The warning is just a warning, not an error.

reddazz · 12-16-2006, 10:26 AM

Can you post the code.

Nylex · 12-16-2006, 10:38 AM

Quote:

Originally Posted by platipo

already tried that; g++ gives me just the same problem, I have none of the lines you mentioned in my program, gonna try now

Edit: using namespace std gives me a load of errors and warnings, while using std::cout removes that error and leaves me with only endl undefined

Obviously you'd need to change endl to std::endl as well..

But yes, please post your code.

platipo · 12-16-2006, 10:44 AM

sure:here it is

#include <iostream>

int main()
{

cout<<"hello world"<<endl;
return 0;
}

this was my original code. I tried using std::endl too, but it gives me the same errors

Nylex · 12-16-2006, 11:09 AM

If you put "using namespace std;" under the include directive, what kind of warnings and errors are you getting? It should work ok. What exactly is the command you're using to compile?

platipo · 12-16-2006, 11:28 AM

I'm simply using gcc filename.cpp, the errors I get are just the same I get with writing using std::cout and using std::endl; it seems I do NOT have iostream in the usr/include folder... and that might just be the problem, still, I tried compiling the same code on another machine with those libraries and... it still doesn't work.

Nylex · 12-16-2006, 11:34 AM

If you're using gcc, you need to link the C++ library. Add a "-lstdc++" to your compile line, or does that not work either?

Not sure about Kubuntu, but under Slack, the header files are in /usr/include/c++/<version>.

reddazz · 12-16-2006, 11:58 AM

The code should be like

Code:

#include <iostream>
using namespace std;
int main()
{

    cout<<"hello world"<<endl;

    return 0;
}

To compile the program, you would do something like

Code:

$g++ -o hello hello.cpp

Tinkster · 12-16-2006, 01:20 PM

Or, just to develop a good habit, (or at least bear it in mind):

Code:

#include <iostream>
int main()
{

    std::cout<<"hello world"<<std::endl;

    return 0;
}

Cheers,
Tink

Tinkster · 12-16-2006, 01:34 PM

And really, this should be in Programming; moving it along.

Cheers,
Tink

platipo · 12-16-2006, 02:05 PM

Quote:

Originally Posted by Tinkster

And really, this should be in Programming; moving it along.

Cheers,
Tink

sorry... it sounded as such a newbie question...
EDIT
btw thanks again, I think I solved the problem.