Lua varaible reader

lua1.cpp

#include <iostream>
#include <lua.hpp>

int main(int argc, char *argv[]) {
  // create a new lua context to work with
  lua_State *L = luaL_newstate();

  // open any library we may use
  luaL_openlibs(L);

  // read the Lua script off disk and execute it
  if ((luaL_dofile(L, "test.lua")) != 0) {
    
    // handle any errors 
    std::cout << "unable to load test.lua" << std::endl;
    return 1;
    
  }

  // put the value of X at the top of the stack
  lua_getglobal(L, "x");
  
  // interpret the value at the top of the stack 
  // as an integer and put it in the variable "val"
  int val = (int)lua_tointeger(L, -1);
  
  // pop the value of X off the stack
  lua_pop(L, 1);

  // write the value out
  std::cout << "Value of X: " << val << std::endl;

  // finish up with the Lua context
  lua_close(L);

  return 0;

}