Example of use lua table in C.

luatableExp.c

#include <stdio.h> 
#include <stdlib.h> 

extern "C" { 
#include "lua.h" 
#include "lauxlib.h" 
#include "lualib.h" 
}

#pragma comment(lib, "liblua.lib")

/*
   -- test.lua
   test = 2222
   keys = {{r = 1}, {r = 2}, {r = 3}, }
*/
int main()
{
    char *luaFile = "test.lua";

    // lua初始化
    lua_State *L = luaL_newstate(); // new api in lua5.2
    luaL_openlibs(L);
    luaL_loadfile(L, luaFile);
    if (lua_pcall(L, 0, LUA_MULTRET, 0) != 0)
    {
        printf("error running file %s: %s", luaFile,
                lua_tostring(L, -1));
    }

    // 读取变量
    lua_getglobal(L, "test");
    int a = lua_tointeger(L, -1);
    printf("test = %d\n", lua_tointeger(L, -1));

    // 遍历table
    lua_getglobal(L, "keys");
    // 取 table 索引值
    int nIndex = lua_gettop(L);
    // nil 入栈作为初始 key
    lua_pushnil(L);
    while (0 != lua_next(L, nIndex))
    {
        // 处理里层的table
        // 取key为r的值
        lua_pushstring(L, "r");
        lua_gettable(L, -2);
        printf("%d\n", lua_tointeger(L, -1));
        // 弹出 value，让 key 留在栈顶
        lua_pop( L, 1 );

        // 这是第一层talbe
        lua_pop( L, 1 );
    }

    // 关闭lua
    lua_close(L);
}