Compile error: Undefined symbols: “_main”, referenced from: start in crt1.10.5.o

Question

I have the following code:

#include 

using namespace std;

class testing{
   int test() const;
   int test1(const testing& test2);
};

int t         


        

Answer 1

You have tried to link it already:

g++ file.cpp

That will not only compile it, but try to already create the executable. The linker then is unable to find the main function that it needs. Well, do it like this:

g++ -c file.cpp
g++ -c hasmain.cpp

That will create two files file.o and hasmain.o, both only compiled so far. Now you can link them together with g++:

g++ -omy_program hasmain.o file.o

It will automatically figure out that those are files already compiled, and invoke the linker on them to create a file "my_program" which is your executable.