Lua 與 C 擴充 -簡單函式

Lua 與 C 擴充-簡單函式

環境
windows 11 64bit
Visual Studio 2022
Lua 5.4.6

C擴充程式碼 – mytestlib.c

#include <K:\Lua\546\lib17\include\lua.h>
#include <K:\Lua\546\lib17\include\lualib.h>
#include <K:\Lua\546\lib17\include\lauxlib.h>
#include <K:\Lua\546\lib17\include\luaconf.h>
#include <string.h>

#pragma comment(lib,"K:\\Lua\\546\\lib17\\x86\\Release\\lua54.lib")

static int luaAdd(lua_State* L)
{
	double p1 = luaL_checknumber(L, 1);
	double p2 = luaL_checknumber(L, 2);
	lua_pushnumber(L, p1 + p2);
	return 1;
}

static int luaSub(lua_State* L)
{
	double p1 = luaL_checknumber(L, 1);
	double p2 = luaL_checknumber(L, 2);
	lua_pushnumber(L, p1 - p2);
	return 1;
}

static int luaHelloString(lua_State* L)
{
	const char* Name = luaL_checkstring(L, 1);
	char sz[128] = "Hello!";
	strcat_s(sz, sizeof(sz), Name);
	lua_pushstring(L, sz);
    return 1;
}

static const luaL_Reg mylibs[] =
{
	{"add", luaAdd},
	{"sub", luaSub},
	{"hello", luaHelloString},
	{NULL, NULL}
};

int __declspec(dllexport) luaopen_mytestlib(lua_State * L)
{
	lua_newtable(L);
	luaL_setfuncs(L, mylibs, 0);
	return 1;
}

1. 最簡單的方式

寫compile指令 – compile.bat

cl /LD /MD mytestlib.c

打開VS的文字控制編譯器 – VC.bat

@echo off
%comspec% /k ""C:\Program Files\Microsoft Visual Studio\2022\Community\VC\Auxiliary\Build\vcvarsall.bat"" x86

打開之後輸入 compile，編譯完成

主要是要產生 mytestlib.dll

test.lua

local mytest = require "mytestlib"

print (mytest.add(1.0,2.0))
print (mytest.sub(1.0,2.0))
print (mytest.hello("Charlie"))

把 mytestlib.dll 和 test.lua 放一起，執行 test.lua 後的結果

2. 用 Visual Studio 2022 產生 mytestlib.dll

這會是 dll 檔的檔名

把剛剛的 mytestlib.c 放進來

不過要修改一下引用的 lib

#ifdef _WIN64
#ifdef _DEBUG
#pragma comment(lib,"K:\\Lua\\546\\lib17\\x64\\Debug\\lua54.lib")
#else
#pragma comment(lib,"K:\\Lua\\546\\lib17\\x64\\Release\\lua54.lib")
#endif
#else
#ifdef _DEBUG
#pragma comment(lib,"K:\\Lua\\546\\lib17\\x86\\Debug\\lua54.lib")
#else
#pragma comment(lib,"K:\\Lua\\546\\lib17\\x86\\Release\\lua54.lib")
#endif
#endif

建置成功之後也是能產生 mytestlib.dll

3. C++

mytestlib.cpp

#include <K:\Lua\546\lib17\include\lua.hpp>

#include <string.h>

#pragma comment(lib,"K:\\Lua\\546\\lib17\\x86\\Release\\lua54.lib")

static int luaAdd(lua_State* L)
{
	double p1 = luaL_checknumber(L, 1);
	double p2 = luaL_checknumber(L, 2);
	lua_pushnumber(L, p1 + p2);
	return 1;
}

static int luaSub(lua_State* L)
{
	double p1 = luaL_checknumber(L, 1);
	double p2 = luaL_checknumber(L, 2);
	lua_pushnumber(L, p1 - p2);
	return 1;
}

static int luaHelloString(lua_State* L)
{
	const char* Name = luaL_checkstring(L, 1);
	char sz[128] = "Hello!";
	strcat_s(sz, sizeof(sz), Name);
	lua_pushstring(L, sz);
    return 1;
}

static const luaL_Reg mylibs[] =
{
	{"add", luaAdd},
	{"sub", luaSub},
	{"hello", luaHelloString},
	{NULL, NULL}
};
extern "C"
{
int __declspec(dllexport) luaopen_mytestlib(lua_State * L)
{
	lua_newtable(L);
	luaL_setfuncs(L, mylibs, 0);
	return 1;
}
}

寫compile指令 – compile.bat

cl /LD /MD mytestlib.cpp

之後的步驟跟前面C的都一樣。

Lua5.2 之後，取消掉了 luaL_register，關於這部分造成的問題，可以參考最下面的網址。

回到目錄
https://husking-studio.com/extending-lua-with-c

參考網址
https://iter01.com/554581.html
http://www.yjxsoft.com/forum.php?mod=viewthread&tid=4384
https://www.136.la/net/show-9708.html