locked_tables

local function lock( t )
    t.__locked = true
    return setmetatable( {}, {
        __index = t,
        __newindex = function( )
            error( "attempt to modify read only table", 2 )
        end,
        __metatable = false,
    })
end

local _rawset = _G.rawset
rawset = function( t, k, v, password )
    if t.__locked then
      error( "attempt to modify read only table", 2 )
    else--#change to else
      return _rawset( t, k, v )
    end
end
_G.rawset = rawset

local t = { "hello" }
t = lock( t )
print( t.__locked )
t.__locked = false --#error!
print(t.__locked )