Environments

[Eva Schmidt <es@...>]

Hello,

I've got a question about the environment mechanism in Lua.

I want to execute a little script from another script using loadfile(). Because 
of the fact that I cannot make sure that this script doesn't contain code I 
don't want to be executed (like os.exit() or something) I tried to just allow 
certain functions using an environment like that:


   -- create local environment for loadstring()
   local fenv = {}
   fenv.print = _G.print

   setfenv (loadstring, fenv)

   result, error = loadstring (s)

With this environment it should be possible to just call the printing function 
within the chunk to be loaded. Maybe this approach is too naive -  Lua forbits 
changing the environment for the function loadstring() ;-(

Does anybody have some idea how I can force Lua to allow the executing of some 
special functions and to prohibit other functions at the same time?

thanks for help!

Eva