Function db_sethook

Source/Misc/lua/src/lua.c:11774–11795

static int db_sethook (lua_State *L) {
int arg, mask, count;
lua_Hook func;
lua_State *L1 = getthread(L, &arg);
if (lua_isnoneornil(L, arg+1)) {
lua_settop(L, arg+1);
func = NULL; mask = 0; count = 0;  /* turn off hooks */
}
else {
const char *smask = luaL_checkstring(L, arg+2);
luaL_checktype(L, arg+1, LUA_TFUNCTION);
count = luaL_optint(L, arg+3, 0);
func = hookf; mask = makemask(smask, count);
}
gethooktable(L);
lua_pushlightuserdata(L, L1);
lua_pushvalue(L, arg+1);
lua_rawset(L, -3);  /* set new hook */
lua_pop(L, 1);  /* remove hook table */
lua_sethook(L1, func, mask, count);  /* set hooks */
return 0;
}


static int db_gethook (lua_State *L) {