This very simple C++ program using the standard library doesn't compile with GCC [duplicate]

Question

I can't figure out why this isn't working...

I am working in Linux.

g++ doesn't do anything.

gcc prints the following:

/tmp/ccyg7NDd.o: In function `main':
test.cc:(.text+0x14): undefined reference to `std::cout'
test.cc:(.text+0x19): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::operator<< <std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&, char const*)'
test.cc:(.text+0x21): undefined reference to `std::basic_ostream<char, std::char_traits<char> >& std::endl<char, std::char_traits<char> >(std::basic_ostream<char, std::char_traits<char> >&)'
test.cc:(.text+0x29): undefined reference to `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> >&))'
/tmp/ccyg7NDd.o: In function `__static_initialization_and_destruction_0(int, int)':
test.cc:(.text+0x51): undefined reference to `std::ios_base::Init::Init()'
test.cc:(.text+0x56): undefined reference to `std::ios_base::Init::~Init()'
/tmp/ccyg7NDd.o:(.eh_frame+0x12): undefined reference to `__gxx_personality_v0'
collect2: ld returned 1 exit status

Code:

#include <iostream>
#include <stdio.h>

int main(){

    std::cout << "test " << std::endl;
    return 0;
};

Sarmiento

What do you mean that g++ doesn't do anything? – Selfevident

gcc is the C compiler, you need to use g++. What do you mean g++ does not do anything? You have to execute the compiled binary after you build it (i.e. when g++ completes). – Wiseman

@hmjd: g++ is gcc, it just automatically links against libstdc++. You can get the same effect with gcc by supplying -lstdc++. – Bremen

What @Wiseman said: after running g++ you want to run the file which, with no other options, is called a.out. – Diorama

by it doesn't do anything I mean it doesn't print to the console...which i think it should – Sarmiento

@spatara: The compiler will only print something if there's a problem. Like most Unix-style programs, silence means success. You should find a program called a.out, or something else if you gave a -o option to the compiler; running that should print test to the console. – Sangfroid

@Sarmiento If you don't like the silence, you can pass the --verbose flag and it'll tell you more than you want to know. – Emera

g++ dosen't do anything? Look at the new file in the folder. Not doing anything is compilation success! – Vernation

Answer 1

g++ main.cpp

or

gcc main.cpp -lstdc++

Porterporterage

Answer 2

gcc is the C compiler. You need to use g++ (or use gcc with option -lstdc++ as pointed out by others). If by nothing is printed after you use g++ is what you mean, you have to execute the compiled binary after you build it (i.e., when g++ completes).

main.cpp:

#include <iostream>

int main(){

    std::cout<<"test "<<std::endl;
    return 0;
};

Build:

g++ main.cpp -o main

Execute:

./main

Output:

test

Wiseman

Answer 3

This is C++ code and so you should use executable g++ and not executable gcc.

Also, #include<stdio.h>, is not needed.

Dauntless

Answer 4

I think you are mistakenly linking with the C compiler command instead of the C++ compiler command. Try this:

g++ test.cc -o test

Null

Answer 5

I think the underlying issue for this is that the binary name "test" is actually already apart of the Linux system. Typing in "man test" displays a manual for the test binary. I had the exact same issue. It was resolved simply by compiling the binary to something other than "test".

Adaurd

But the real issue was that "test" was used instead of "./test"(?). The canonical question is How can I compile and run C/C++ code in a Unix console or Mac terminal?. – Vulcanism