first program in *nix

System_159 · 09-12-2007, 03:38 PM

Edit: Ok, so I should have been using g++ instead of gcc for the .cpp file. That's settled. New question though, how do I link files that I have included? Say if I write a program and I want to include curses.h, how do I compile that?

Everything below this is the original question.

Hi all. Up until this point I've always written and compiled my programs in Windows. I got a Macbook Pro a couple of months ago, and figure it's time to start programming in Unix. I'm not very advanced in terminal, so it took me a bit of time to try to even get to the proper directory. I finally got the commands correct to compile but I got errors on everything, including a hello world program!

Every time I try to compile something I get this:

Code:

/usr/bin/ld: Undefined symbols:

And a bunch of stuff depending on what I'm trying to compile

for

Code:

#include <iostream>
using namespace std;

int main( int argc, char *argv[] )
{
    cout << "Hello World" << endl;
    return 0;
}

I get this in the terminal:

Code:

current directory$ gcc -o helloworld helloworld.cpp
/usr/bin/ld: Undefined symbols:
std::basic_ostream<char, std::char_traits<char> >::operator<<(std::basic_ostream<char, std::char_traits<char> >& (*)(std::basic_ostream<char, std::char_traits<char> >&))
std::ios_base::Init::Init()
std::ios_base::Init::~Init()
std::cout
std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)
std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)
___gxx_personality_v0
collect2: ld returned 1 exit status

I have no idea what most of this means. Is there a reason why such a simple program won't compile? I know it's probably something stupidly simple, but as I've never worked in this environment before, it's totally beyond me.

If anybody can offer some advice, or show me a good starters guide to writing/compiling c/c++ in *nix, that be great.

Thanks so much.

Ed

**Salem** · 09-12-2007, 04:17 PM

g++ prog.cpp -lcurses

System_159 · 09-12-2007, 06:23 PM

Quote:

Originally Posted by Salem

g++ prog.cpp -lcurses

Thanks. That solved the curses.h linker error. What do I for custom header files? I've got three header files that I'm including:

Code:

#include "includes/mnemonics.h" 
#include "gui/draw_menu.h"
#include "gui/menus.h"

Thanks again for the help Salem. I'm currently fiddling around with the system while I wait to find out how to link those headers.

ssharish2005 · 09-12-2007, 06:50 PM

Code:

g++ -I../includes../gui -o helloworld helloworld.cpp -lcurses

ssharish

zacs7 · 09-12-2007, 10:12 PM

Do nothing with the custom header files, leave them as they are, don't attempt to compile them seperatly (ie just leave the compiler switches as they are).

You may also want to turn up the warning level and stuff, do a man gcc

You don't need to specify -I, because you explicitly define the directory where the headers are.

Quote:

Originally Posted by man gcc

-I dir
Add the directory dir to the list of directories to be
searched for header files. Directories named by -I are
searched before the standard system include directories.
If the directory dir is a standard system include
directory, the option is ignored to ensure that the
default search order for system directories and the
special treatment of system headers are not defeated .

09-12-2007, 03:38 PM	#1
System_159 Registered User Join Date: Aug 2006 Posts: 159	*first program in nix** Edit: Ok, so I should have been using g++ instead of gcc for the .cpp file. That's settled. New question though, how do I link files that I have included? Say if I write a program and I want to include curses.h, how do I compile that? Everything below this is the original question. Hi all. Up until this point I've always written and compiled my programs in Windows. I got a Macbook Pro a couple of months ago, and figure it's time to start programming in Unix. I'm not very advanced in terminal, so it took me a bit of time to try to even get to the proper directory. I finally got the commands correct to compile but I got errors on everything, including a hello world program! Every time I try to compile something I get this: Code: /usr/bin/ld: Undefined symbols: And a bunch of stuff depending on what I'm trying to compile for Code: #include <iostream> using namespace std; int main( int argc, char argv[] ) { cout << "Hello World" << endl; return 0; } I get this in the terminal: Code: current directory$ gcc -o helloworld helloworld.cpp /usr/bin/ld: Undefined symbols: std::basic_ostream<char, std::char_traits<char> >::operator<<(std::basic_ostream<char, std::char_traits<char> >& ()(std::basic_ostream<char, std::char_traits<char> >&)) std::ios_base::Init::Init() std::ios_base::Init::~Init() std::cout std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&) std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const) ___gxx_personality_v0 collect2: ld returned 1 exit status I have no idea what most of this means. Is there a reason why such a simple program won't compile? I know it's probably something stupidly simple, but as I've never worked in this environment before, it's totally beyond me. If anybody can offer some advice, or show me a good starters guide to writing/compiling c/c++ in nix, that be great. Thanks so much. Ed Last edited by System_159; 09-12-2007 at 04:09 PM. Reason: answered previous question, new question added
System_159 is offline

09-12-2007, 04:17 PM	#2
Salem and the hat of Jobseeking Join Date: Aug 2001 Location: The edge of the known universe Posts: 21,680	g++ prog.cpp -lcurses __________________ If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
Salem is offline

09-12-2007, 06:50 PM	#4
ssharish2005 Protocol Test Engineer Join Date: Sep 2005 Location: fseek(UK) Posts: 1,324	Code: g++ -I../includes../gui -o helloworld helloworld.cpp -lcurses ssharish Last edited by ssharish2005; 09-12-2007 at 06:55 PM.
ssharish2005 is offline

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Issue with program that's calling a function and has a loop	tigerfansince84	C++ Programming	9	11-12-2008 01:38 PM
Need help with a program, theres something in it for you	engstudent363	C Programming	1	02-29-2008 01:41 PM
This is a simple program.. Help me please I think it has an error..	lesrhac03	C Programming	4	02-21-2008 10:39 AM
My program, anyhelp	@licomb	C Programming	14	08-14-2001 10:04 PM