#include <lua.h>

#include <lauxlib.h>

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#include <getopt.h>

#define ERROR(x) { lua_pushstring(l, x); lua_error(l); }

#define getn(L,n) (luaL_checktype(L, n, LUA_TTABLE), luaL_getn(L, n))

int get_call_stack_size(lua_State *l)

{

int level = 0;

lua_Debug ar;

while (1) {

if (lua_getstack(l, level, &ar) == 0) return level;

level++;

}

/* NOTREACHED */

}

void set_lua_variable(lua_State *l, char *name, int value)

{

/* See if there's a local variable that matches the given name.

* If we find it, then set the value. If not, we'll keep walking back

* up the stack levels until we've exhausted all of the closures.

* At that point, set a global instead. */

lua_Debug ar;

int stacksize = get_call_stack_size(l);

int stacklevel,i;

/* This C call is stacklevel 0; the function that called is, 1; and so on. */

for (stacklevel=0; stacklevel<stacksize; stacklevel++) {

const char *local_name;

lua_getstack(l, stacklevel, &ar);

lua_getinfo(l, "nSluf", &ar); /* get all the info there is. Could probably be whittled down. */

i=1;

while ( (local_name=lua_getlocal(l, &ar, i++)) ) {

if (!strcmp(name, local_name)) {

/* Found the local! Set it, and exit. */

lua_pop(l, 1); // pop the local's old value

lua_pushinteger(l, value); // push the new value

lua_setlocal(l, &ar, i-1); // set the value (note: i was incremented)

lua_pop(l, 2);

return;

}

lua_pop(l, 1);

}

}

/* Didn't find a local with that name anywhere. Set it as a global. */

lua_pushinteger(l, value);

lua_setglobal(l, name);

lua_pop(l, 3);

}