Lua C 5.1 - Iterating through all global values

Recently I have been exploring the luac 5.1 api and I was wondering if it is possible to loop through every global value in the 5.1 api, I know it is possible to do this in 5.2 ( referenced here ) as lua_pushglobaltable(lua_State*) exists. I know there is LUA_GLOBALSINDEX however I'm not sure how to use it for this purpose. Any help would be greatly appreciated!

Thanks :)

You can use the code in the answer you've mentioned. Just do this:

#define lua_pushglobaltable(L) lua_pushvalue(L,LUA_GLOBALSINDEX)

Here is a complete program that lists all global variables. If you remove the define, it works in Lua 5.2 and 5.3.

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

#define lua_pushglobaltable(L) lua_pushvalue(L,LUA_GLOBALSINDEX)

int main(void)
{
    lua_State *L=luaL_newstate();
    luaL_openlibs(L);
    lua_pushglobaltable(L);
    lua_pushnil(L);
    while (lua_next(L,-2) != 0) {
        puts(lua_tostring(L,-2));
        lua_pop(L,1);
    }
    lua_pop(L,1);
    lua_close(L);
    return 0;
}