Re: Extending Lua

[Oliver Kroth <oliver.kroth@...>]

Hi,

you need to return the table instead of making it a global value
--
Oliver

Am 27.10.2016 um 11:28 schrieb Ervin Hegedüs:
> Hi Folks,
>
> I'ld like to extend Lua (with a new module), with an existing C codes. 
> I'm using Lua 5.2 on Linux.
>
> Here is how I try:
>
> ==%==
> luamodule.c:
> -------------------
> #include "lua.h"
> #include "luaconf.h"
> #include "lauxlib.h"
>
> #include "example1.h"  // contains variable and function declarations
>
> static int _wrap_get_str (lua_State *L) {
>     const char *s = luaL_checkstring(L, 1);
>     char retstr[1024];
>
>     get_str(s, retstr);
>     printf("retstr: '%s'\n", retstr);
>     return 0;
> }
>
> void luaopen_example2(lua_State *L) {
>     static const struct luaL_Reg example2[] = {
>       { "get_str", _wrap_get_str },
>       { NULL, NULL }
>     };
>     luaL_newlib(L, example2);
>     lua_setglobal(L, "example2");
> }
> ==%==
>
> Compiling with this statement:
> gcc -g -Wall -shared -fPIC example1.c luamodule.c -o example2.so 
> -I/usr/include/lua5.2 -llua5.2 -lm -ldl
>
> My Lua script:
>
> ==%==
> #!/usr/bin/lua
>
> example2 = require("example2")
> ==%==
>
> and then the example2 will be a "true" (boolean) evaulated variable, 
> not a table. So, when I calling example2.get_str("foo"), then I get an 
> error message:
>
> attempt to index global 'example2' (a boolean value)
>
>
> What's wrong with my code?
>
>
> Thanks,
>
> a.