help.lua

local component = require('component')
local gpu = component.gpu

local width, height = gpu.getResolution()
local maxSize = 0
local maxAddress = ""
for address,type in component.list("screen", true) do
  local proxy = component.proxy(address)
  local width, height = proxy.getAspectRatio()
  local size = width*height
  if proxy ~= nil and size > maxSize then
    maxSize = size
    maxAddress = address
  end
end
gpu.bind(maxAddress)

local filesystem = require('filesystem')
local confdir = "/raid"
local success = false
local error = ""
if not filesystem.exists(confdir) then
  for address,type in component.list("filesystem", true) do
    local proxy = component.proxy(address)
    if proxy ~= nil and proxy.exists("help.conf") then
      --print(address, proxy)
      success, error = filesystem.mount(proxy, confdir)
      break
    end
  end
end
if success == nil then
  print("An error occurred loading the filesystem: " .. error)
  return
end

local confpath = filesystem.concat(confdir, "help.conf")

if not success and not filesystem.exists(confpath) then
  print("No filesystem was found with a help.conf in the main directory")
  return
end

local lastupdated = filesystem.lastModified(confpath)

--print(filesystem.exists("/home/raid/help.conf"))

function loadConf()
  local conf = io.open(confpath)
  --reads pairs of lines
  --the starting coords and the file name to read from
  x = conf:read("*n")
  while (x) do
    y = conf:read("*n")
    filename = string.sub(conf:read(),2)
    --print("raid/"..filename,x,y)

    display(filesystem.concat(confdir, filename),x,y)

    x = conf:read("*n")
  end
  conf:close()

end

--detects if the help.conf file has updated to change position of text on screen
function hasUpdated()
  time = filesystem.lastModified(confpath)
  if time > lastupdated then
    lastupdated = time
    return true
  end

  conf = io.open(confpath)
  if conf == nil then
    return false
  end

  x = conf:read("*n")
  while x do
    conf:read("*n")
    filename = string.sub(conf:read(),2)

    time = filesystem.lastModified(confdir..filename)
    if time > lastupdated then
      lastupdated = time
      return true
    end


    x = conf:read("*n")
  end

  conf:close()
  return false
end

function display(filename,x,y)
  col1 = io.lines(filename)
  displayText(col1,x,y)
end

function displayText(strs, startX, startY)
  k = startY
  for v in strs do
    gpu.set(startX,k,v)
    k=k+1
  end
end

gpu.fill(1,1,width,height, " ")
while 1 do
  sleeptime = 5

  if hasUpdated() then
    gpu.fill(1, 1, width, height, " ")
    loadConf()
    os.sleep(sleeptime)
  else
    loadConf()
    os.sleep(sleeptime)
  end
end