node.js C++ , call so(Shared Object) function

README.md

node.js C++ , call so(Shared Object) function

---

• node setup

npm init -y
npm i koffi

---

• C++ build

g++ -shared -fPIC sample.cpp -o libsample.so

---

• start

node main

---

main.js

const koffi = require('koffi');

// so をロード
const lib = koffi.load('./libsample.so');

// 関数シグネチャを定義 (extern "C" 前提)
const myFunc = lib.func('int add(int a, int b)');
const myGreet = lib.func('const char* greet(const char* name)');

// 呼び出し
const result = myFunc(10, 25);
console.log("myFunc:", result);
const resp_greet = myGreet("hello-123");
console.log("myGreet:" ,resp_greet);

package.json

{
  "name": "so_test1",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "koffi": "^3.0.2"
  }
}

sample.cpp

#include <iostream>
#include <string> // 文字列を扱うために必要
#include <cstring>

extern "C" {

int add(int a, int b)
{
    return a + b;
}

const char* hello()
{
    return "Hello From C++";
}

const char* greet(const char* name)
{
    static std::string msg;
    msg = "Hello ";
    msg += name;
    return msg.c_str();
}


}