Door lock with floppy disk keycard (clearner)

password = "secretdoorpassword!"
debug_char = "0"

term.clear()

function mainLoop()
    while(true) do
        event, driveSide = os.pullEventRaw()
        if(event=="disk" and driveSide) then
            path = disk.getMountPath(driveSide)
            if(path) then
                path = path.."/secretdoor"
                file = fs.exists(path) and io.open(path, "r") or nil
            end
            disk.eject(driveSide)
            if(file and file:read()==password) then
                rs.setOutput("left", true)
                sleep(3)
                rs.setOutput("left", false)         end
            if(file) then file:close() file = nil end
            elseif(debug_char and event=="char" and driveSide==debug_char) then return("break") end
        end
    end

    rs.setOutput("top", true)
        rs.setOutput("back", true)
    sfile = io.open("/startup", "w")
    sfile:write('shell.run("password­")')
    sfile:close()

    repeat
        ok, err, val = pcall(mainLoop)
        if(not ok and err) then
            if(err=="Terminated") then print ("Access denied.")
            else
                print(err)
            end
        end
    until(ok and err=="break")