简单的嵌入lua，留作模板吧……

lua.c

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

#define TOY_MODULE_NAME "toy"

static int l_toy_new(lua_State *L) {
    double value;
    double *toy_obj;

    value = luaL_checknumber(L, 1);

    toy_obj = lua_newuserdata(L, sizeof(double));
    *toy_obj = value;

    luaL_getmetatable(L, TOY_MODULE_NAME);
    lua_setmetatable(L, -2);

    printf("Hello, %f\n", value);

    return 1;
}

static int l_toy_gc(lua_State *L) {
    double *user_data = luaL_checkudata(L, 1, TOY_MODULE_NAME);
    printf("goodbye, %f\n", *user_data);

    return 0; 
}

static int l_toy_sin(lua_State *L) {
    double *arg = luaL_checkudata(L, -1, TOY_MODULE_NAME);

    lua_pushnumber(L, sin(*arg));

    return 1;
}

static luaL_Reg l_toy_meta_functions[] = {
    { "sin", l_toy_sin },
    { "__gc", l_toy_gc },
    { NULL, NULL }
};

static luaL_Reg l_toy_module_functions[] = {
    { "new", l_toy_new },
    { NULL, NULL }
};

static int l_toy_module(lua_State *L) {
    lua_newtable(L);
    luaL_setfuncs(L, l_toy_module_functions, 0);

    return 1;
}

static void l_register_toy(lua_State *L) {
    luaL_newmetatable(L, TOY_MODULE_NAME);
    {
        lua_pushstring(L, "__index");
        lua_pushvalue(L, -2);
        lua_settable(L, -3);

        luaL_setfuncs(L, l_toy_meta_functions, 0);
    }
    lua_pop(L, 1);

    luaL_requiref(L, "toy", l_toy_module, 0);
    lua_pop(L, 1);
}

int main(int argc, char** argv) {
    lua_State *L = luaL_newstate();
    luaL_openlibs(L);

    l_register_toy(L);

    printf("%d\n", lua_gettop(L));
    if (luaL_dofile(L, "test.lua")) {
        printf("%s\n", luaL_checkstring(L, -1));
    }
    printf("%d\n", lua_gettop(L));

    lua_close(L);

    return 0;
}