RE: setfenv, how to...

["Kevin Baca" <lualist@...>]

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.
> > >
> >
> >
>