c函式宣告要符合型別：typedef int (*lua_CFunction) (lua_State *L);
1.在c程式碼執行環境下執行lua程式碼。

#include <stdio.h>
#include <string.h>
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>

static int cadd(lua_State* L)
{

    double op1 = luaL_checknumber(L,1);
    double op2 = luaL_checknumber(L,2
 
);

    lua_pushnumber(L,op1 + op2);

    return 1;
 }

const char* testfunc = "print(cadd(1.0,2.0))";

int main()
 {
    lua_State* L = luaL_newstate();
    luaL_openlibs(L);

    lua_register(L, "cadd", cadd);
    if (luaL_dostring(L,testfunc))
         printf("Failed to invoke.\n");
     lua_close(L);
     return
 
 0;
 }

2.引用c動態庫

#include <stdio.h>
#include "lua.h"
#include "lualib.h"
#include "lauxlib.h"
static int add(lua_State *L)
{
    int a,b,c;
    a = lua_tonumber(L,1);
    b = lua_tonumber(L,2);
    c = a+b;
    lua_pushnumber(L,c);
    printf("test hello!!!\r\n");
    return 1;
}
static const
 
 struct luaL_Reg lib[] =
{
    {"testadd",add},
    {NULL,NULL}
};        

int luaopen_testlib(lua_State *L)
{        
    luaL_register(L,"testlib",lib);
    return 1; 
}        

編譯: gcc test.c -fPIC -shared -o testlib.so

lua指令碼編寫:

require("testlib")
c = testlib.testadd(10,24)
print("The result is ",c);