Re: Getting values in C++ from a Lua table

[Florian Berger <fberger@...>]

Jose Marin wrote:

> The problem is how to get tha values of the table from
> a C++ program...

Hi.

I made following example (see below). I hope it helps.

Regards
Floru


run.lua:
level1 =
{
  music = "music1",

  items =
  {
    A = 1,
    B = 2,

    {
      c = "C",
    }
  }
}


main.cpp:
#include <stdio.h>

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

// In Lua 5.0 reference manual is a table traversal example at page 29.
void PrintTable(lua_State *L)
{
    lua_pushnil(L);

    while(lua_next(L, -2) != 0)
    {
        if(lua_isstring(L, -1))
          printf("%s = %s\n", lua_tostring(L, -2), lua_tostring(L, -1));
        else if(lua_isnumber(L, -1))
          printf("%s = %d\n", lua_tostring(L, -2), lua_tonumber(L, -1));
        else if(lua_istable(L, -1))
          PrintTable(L);

        lua_pop(L, 1);
    }
}


void main()
{
    lua_State *L = lua_open();

    // Load file.
    if(luaL_loadfile(L, "run.lua") || lua_pcall(L, 0, 0, 0))
    {
        printf("Cannot run file\n");
        return;
    }

    // Print table contents.
    lua_getglobal(L, "level1");
    PrintTable(L);

    // Print music field.
    lua_getglobal(L, "level1");
    lua_pushstring(L, "music");
    lua_gettable(L, -2);

    if(lua_isstring(L, -1))
        printf("\nlevel1.music = %s\n", lua_tostring(L, -1));

    lua_close(L);
}


Result:
c = C
A = 1
B = 2
music = music1

level1.music = music1