[ComputerCraft] safeString

local function safeString(text)
                local newText = {}
                for i = 1, #text do
                        local val = text:byte(i)
                        newText[i] = (val > 31 and val < 127) and val or 63
                end
                return string.char(unpack(newText))
        end

print(safeString("é")) --Will print "??"