CC server

serverID = os.getComputerID
userIDs = {}
userIDsN = 0

function manageUsers()
   local menu = "\nManaging users:\n"
   menu = menu .. "0. Back\n"
   menu = menu .. "1. Show users\n"
   menu = menu .. "2. Add users\n"
   menu = menu .. "3. Remove users\n\n"
   menu = menu .. "Your choice: "
   io.write(menu)
   choice = io.read("*l");
   while choice ~= "0" do
      if choice == "0" then
         break
      elseif choice == "1" then
         showUsers()
      elseif choice == "2" then
         addUsers()
      elseif choice == "3" then
         removeUsers()
      end
      io.write(menu)
      choice = io.read("*l");
   end
end

function showUsers()
   io.write("\n")
   for i,v in ipairs(userIDs) do
      io.write("userID[" .. i .. "]: " .. v .. "\n")
   end
end

function addUsers()
   local input = io.read("*l")
   while input ~= "." do
      local id = tonumber(input)
      userIDsN = userIDsN + 1
      userIDs[userIDsN] = id
      input = io.read("*l")
   end
   updateUserIDsfile()
end

function removeUsers()
   local input = io.read("*l")
   while input ~= "." do
      local id = tonumber(id)
      for i = id, userIDsN - 1 do
         userIDs[i] = userIDs[i + 1]
      end
      userIDs[userIDsN] = nil
      userIDsN = userIDsN - 1
      input = io.read("*l")
   end
   updateUserIDsfile()
end

function writeToFile(path,data)
   local file = fs.open(path,"w")
   file.write(textutils.serialise(data))
   file.close()
end

function readFromFile(path)
   local file = fs.open(path,"r")
   data = textutils.unserialise(file.readAll())
   file.close()
   return data
end

function updateUserIDsfile()
   writeToFile("data/userIDs",userIDs)
end

function updateUserIDs()
   if fs.exists("data/userIDs") then
      userIDs = readFromFile("data/userIDs")
      userIDsN = table.getn(userIDs)
   end
end

function init()
   updateUserIDs()
end

function loop()
   init()
   local menu = "\nMenu:\n"
   menu = menu .. "0. Close\n"
   menu = menu .. "1. Manage users\n\n"
   menu = menu .. "Your choice: "
   io.write(menu)
   choice = io.read("*l");
   while choice ~= "0" do
      if choice == "0" then
         break
      elseif choice == "1" then
         manageUsers()
      elseif choice == "2" then
         showUsers()
      end
      io.write(menu)
      choice = io.read("*l");
   end
end

loop()