Re: Calling Lua from C

[Rici Lake <lua@...>]

You should turn on more warnings in your c compiler. A good c compiler 
would have told you that you cannot use a %d format code with a 
floating-point argument. :)

(I have no idea where the 5 comes from, though. Of course, it very much 
depends on the architecture you are using.)

On 8-Oct-05, at 6:43 PM, Chris wrote:

> Hi, I'm fairly new to Lua and this issue is driving me insane.  I'm 
> trying to call table.getn() from C which seems to work on the Lua side 
> but not inside the C code (see below).  Here is the code in question:
>
>  First the C function:
>
>  static int TestCall(lua_State* L)
>  {
>     lua_pushstring(L, "table");
>     lua_gettable(L, LUA_GLOBALSINDEX);
>     lua_pushstring(L, "getn");
>     lua_gettable(L, -2);
>     lua_pushvalue(L, 1);
>     lua_call(L, 1, 1);
>     lua_remove(L, -2);
>
>     printf("c_num: %d, %d\n", lua_isnumber(L, -1), lua_tonumber(L, 
> -1));
>     return 1;
>  }
>
>  And the Lua code:
>
>  sometable = {}
>  sometable[1] = 1;
>  sometable[2] = 2;
>  print(TestCall(sometable))
>
>  Now what this prints out when run is:
>
>  c_num: 1, 5
>  2
>
>  Meaning the stack value for the number of elements is 5 on the C side 
> but magically turns into the correct value of 2 back in Lua.  WTF?
>
>  Thanks for any help...