Lua呼叫C++動態連結庫.so
阿新 • • 發佈:2021-10-14
c++程式碼// testlib.cpp
#include <iostream>
#include <lua.hpp>
using namespace std;
/* 定義C++的Average 函式 */
int average(lua_State *L)
{
int num = lua_gettop(L); //獲取引數個數
double sum = 0;
double avg = 0;
for(int i = 1; i <= num; i++) //注意Lua棧下標從1開始
{
sum += lua_tonumber(L, i); // 求和
}
avg = sum / num; //求平均
lua_pushnumber(L, avg); //平均值入棧
lua_pushnumber(L, sum); //和入棧
int size = lua_gettop(L);
for(int i=1;i<=size;i++)
{
printf("[%d] = %f\n",i, lua_tonumber(L, i));
}
return 2; //return 返回值個數
}
/* 定義C++的sub函式 */
int sub(lua_State *L)
{
int num = lua_gettop(L);
if(num != 2)
{
cout << "Input param number is not correct!" << endl;
return 0;
}
int a = lua_tonumber(L, 1); //獲取第一個引數,被減數
int b = lua_tonumber(L, 2); //獲取第二個引數,減數
int diff = a - b;
lua_pushnumber(L, diff); //結果壓入棧
return 1;
}
/* 定義C++的add函式 */
int add(lua_State *L)
{
int num = lua_gettop(L);
if(num != 2)
{
cout << "Input param number is not correct!" << endl;
return 0;
}
int a = lua_tonumber(L, 1); //獲取第一個引數,被減數
int b = lua_tonumber(L, 2); //獲取第二個引數,減數
int sum = a + b;
lua_pushnumber(L, sum); //結果壓入棧
return 1;
}
//使用luaL_Reg註冊新的C函式到Lua中
static const luaL_Reg test_functions[] =
{
{"average", average},
{"add", add},
{"sub", sub},
{NULL, NULL} //陣列中最後一對必須是{NULL, NULL},用來表示結束
};
/* luaopen_XXX,XXX為庫名稱,若庫名稱為testlib.so,XXX即為testlib */
//luaopen_testlib函式前要加上 extern "C" 匯出函式名才能被lua呼叫
//要不然在lua require的時候會報錯找不到luaopen_testlib
extern "C" int luaopen_testlib(lua_State *L)
{
luaL_newlib(L, test_functions); //Lua 5.2之後用luaL_newlib代替了luaL_register
return 1;
}
makefile
testlib.so: testlib.h testlib.cpp
g++ -std=c++11 -shared -fPIC testlib.cpp -o testlib.so -I /usr/local/include/lua -llua -ldl
clean:
rm -f testlib.so
注:
-I /usr/local/include/lua ---> 指明要連結的lua標頭檔案的路徑
在執行make命令之前需要利用lua原始碼編譯出靜態庫(.a)或者動態庫(.so)放在同級目錄下,
要不然在執行make編譯testlib.so時會報很多lua介面函式找不到
lua呼叫
local abc = require("testlib")
avg,sum = abc.average(100, 200, 300, 400, 500)
diff = abc.sub(100,50)
total = abc.add(100,50)
print("avg = ",avg)
print("sum =",sum)
print("diff = ",diff)
print("total = ",total)