node.js windows , DLL call example

README.md

node.js windows , DLL call example

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• npm install

npm i koffi

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• C++ build

clang++ -shared sample.cpp -o sample.dll

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• start

node main

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main.js

const koffi = require('koffi');

// DLLのロード（.dll拡張子は省略可）
const lib = koffi.load('./sample.dll');

// 関数の定義: 戻り値型, 関数名, [引数型...]
const add = lib.func('int add(int a, int b)');
const multiply = lib.func('double multiply(double a, double b)');
const getMessage = lib.func('const char* get_message()');
const greet = lib.func('const char* greet(const char* name)');

// 実行
console.log(add(3, 5));         // 8
console.log(multiply(2.5, 4));  // 10.0
console.log(getMessage());  // 10.0
const g1 = greet("テスト文字-TEST-001");
console.log("g1=", g1);

sample.cpp

#include <windows.h>
#include <string>

// extern "C" でC言語リンクとし、__declspec(dllexport) でエクスポート
extern "C" {
    __declspec(dllexport) int add(int a, int b) {
        return a + b;
    }

    __declspec(dllexport) double multiply(double a, double b) {
        return a * b;
    }

    __declspec(dllexport) const char* get_message()
    {
        return "Hello World";
    }

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

}