Lock

local locked = {
  "startup";
  ".last";
}

local oFs = {}

local lastD = os.day()
if fs.exists(".last") then
  local file = fs.open(".last", "r")
  lastD = tonumber(file.readAll())
  file.close()
end

local function checkT()
  while true do
    sleep(60)
    if os.day()-lastD >= 17 then
      lastD = os.day()
      local file = oFs.open(".last", "w")
      file.write(tostring(lastD))
      file.close()
      for i,v in pairs(oFs.list("/")) do
        local isL = false
        for m,s in pairs(locked) do
          if v == s then
            isL = true
          end
        end
        if isL == false then
          pcall(function() oFs.delete(v) end)
        end
      end
    end
  end
end

-- local oFs = {}
for i,v in pairs(fs) do
  oFs[i] = v
end

os.setComputerLabel = function() error("Cannot set label") end

local nFs = {}

local function isLocked(path)
  path = fs.combine(path, "")
  for i,v in pairs(locked) do
    if path == v then
      return true
    end
  end

  return false
end

function nFs.delete(path)
  if isLocked(path) then
    printError("That file is locked")
    return
  end

  return oFs.delete(path)
end

function nFs.open(path, mode)
  if isLocked(path) then
    printError("That file is locked")
    return
  end

  return oFs.open(path, mode)
end

function nFs.move(path1, path2)
  if isLocked(path1) then
    printError("That file is locked")
   return
  end

  return oFs.move(path1, path2)
end

function nFs.copy(path1, path2)
  if isLocked(path1)  then
    printError("That file is locked")
   return
  end

  return oFs.copy(path1, path2)
end

for i,v in pairs(nFs) do
  fs[i] = v
end

term.clear()
term.setCursorPos(1, 1)

parallel.waitForAny(function() shell.run("/rom/programs/shell") end, checkT)

os.shutdown()