Re: setfenv, how to...

["Pedro" <pedro@...>]

Or take a look at 

http://tcs01.les.inf.puc-rio.br/wiki/w/LuaLanguage/ScriptSandboxing 

It's simple, but so far it does seem to work well. Other people with whom 
I've spoken about the subject might have better suggestions. 

Cheers and good luck. 

Pedro. 

Kevin Baca writes: 

> tab = {} 
>
> for k,v in pairs( _G ) do
>     tab[ k ] = v
> end 
>
> -- Remove restricted functions
> tab.rawget = nil
> tab.rawset = nil
> tab.setmetatable = nil
> ... 
>
> Basically, populate a table with the subset of functions that are not
> restricted. 
>
> Also, search for "sandbox" in the archives for some interesting
> discussions. 
>
> -Kevin 
>
>
> > -----Original Message-----
> > From: lua-bounces@bazar2.conectiva.com.br 
> > [mailto:lua-bounces@bazar2.conectiva.com.br] On Behalf Of 
> > Leandro Candido
> > Sent: Thursday, November 13, 2003 10:38 AM
> > To: Lua list
> > Subject: Re: setfenv, how to... 
> >
> >
> > Hello, 
> >
> >     Thank you, but this is what I'm trying to avoid ;-), I 
> > don't want to allow access to the global enviromment, only to 
> > tab, what I want is to protect the global table.
> >     My intent is to make tab.afunc use as global table tab, 
> > but switch to real global table when calling print. Of 
> > course, when afunc call print, it's tab.print but i want to 
> > it call the real print. Really, at momment it's a hard task, 
> > or impossible to do. 
> >
> >                                                               
> >           The God's Peace, 
> >
> >
> > Leandro. 
> >
> > ----- Original Message -----
> > From: "Kevin Baca" <lualist@aidiastudios.com>
> > To: "'Lua list'" <lua@bazar2.conectiva.com.br>
> > Sent: Monday, November 10, 2003 8:41 PM
> > Subject: RE: setfenv, how to... 
> >
> >
> > > tab = setmetatable( {}, { __index = _G } )
> > >
> > > > ... Let a function with an enviromment call another with other 
> > > > enviromment?
> > > > Example:
> > > > -- block
> > > >     tab = {}
> > > >     function tab.afunc()
> > > >         print("Inside tab.afunc");
> > > >     end
> > > >     setfenv(tab.afunc, tab);
> > > > -- end block
> > > >
> > > >     The code above raise an error with "attempt to call global 
> > > > 'print' (a nil value)". Yes, I know that the code is 
> > trying to call 
> > > > tab.print, but how to set it to call the real print? 
> > (Please, I know 
> > > > too that I can write tab.print = print; but this isn't 
> > what I want).
> > > >
> > > >
> > > >           The God's Peace,
> > > >
> > > >
> > > > Leandro.
> > > >
> > >
> > > 
>