Compiling source with static and shared library

how_to.md

// bin_hello.cpp

#include "lib_hello.h"

int main() {
    hello_world();
}

// lib_hello.cpp

#include <iostream>

void hello_world() {
    std::cout << "Hello World!";
}

// lib_hello.h

extern void hello_world();

---

• Compiling with static library:

$ g++ bin_hello.cpp lib_hello.cpp -o hello_world
$ ./hello_world
Hello World!

• Compiling with shared library:

$ g++ -shared -fPIC lib_hello.cpp -o lib_hello.so
$ g++ bin_hello.cpp lib_hello.so -o hello_world
$ LD_LIBRARY_PATH=$(pwd) ./hello_world
Hello World!