RE: Using part of a Lua script from C

["Elbers, H.P." <H.P.Elbers@...>]

Hi Evan,

You can test the the value of 'arg':
When using the interpreter arg[-1] will be Lua, argv[0] will be the name
of your script. 
When loaded with luaL_dofile (or luaL_loadfile), arg will be nil.

--code to allow the script to run stand-alone:
if arg then
  a = 1
  b = 2
  filter(a,b)
end

HtH, Hans Elbers.

> -----Original Message-----
> From: lua-bounces@bazar2.conectiva.com.br 
> [mailto:lua-bounces@bazar2.conectiva.com.br] On Behalf Of Evan Burkitt
> Sent: dinsdag 4 augustus 2009 6:12
> To: lua@bazar2.conectiva.com.br
> Subject: Using part of a Lua script from C
> 
> I have an application that calls functions in Lua scripts 
> from C (C++, actually). My design expects a certain function, 
> "filter()", to exist in the scripts it uses. filter() 
> typically calls other functions in the script as part of its 
> behavior, but the C/C++ code doesn't know of or use these 
> other functions.
> 
> The scripts also contain a section of code that calls 
> filter(). This exists so the script as a whole can be run 
> stand-alone via the lua command line.
> 
> Here's a minimal illustration of what my lua script looks like:
> --internal functions:
> function internal1() end
> function internal2() end
> 
> --function called by C/C++:
> function filter(a,b)
>    internal1()
>    internal2()
> end
> 
> --code to allow the script to run stand-alone:
> a = 1
> b = 2
> filter(a,b)
> 
> When I load and compile the script via luaL_loadfile() and 
> lua_pcall(), the code at the end begins to execute when I 
> call lua_pcall().
> 
> My question is, what is the best way to process the script 
> file so that my C/C++ code can call filter() yet the entire 
> script does get executed in the process?
> 
> -evan
> 
>