Universal Program Updater API v0.3

--[[
  0.3
  ^^ Do not touch ANYTHING above this line ^^
  Universal Program Updater API
  By: TisTheeIntrepid(Firestorm002)
]]
--Functions--
--Grabs the running programs path and name.
function getRunningPath(runPath)
  local runningProgram = runPath
  local programName = fs.getName(runningProgram)
  return runningProgram:sub(1,#runningProgram - #programName),programName
end
--Runs the actually updating part of the process and uses the specified 'pasteBinRawURL'.
function updater(pasteBinRawURL,runPath)
    print("Updating...")
  local httpPage = http.get(pasteBinRawURL)
  local downloadedProgram = httpPage.readAll()
  local pPath, pName = getRunningPath(runPath)
    print("Downloading new version to '"..pPath..pName.."'!")
  local dFile = fs.open(pPath..pName,"w")
  dFile.write(downloadedProgram)
  dFile.close()
end
--Checks the version number on line 2 of your program to the program's pastebin page
-- via line 2.
function verCheck(pasteBinRawURL,runPath)
  local httpPage = http.get(pasteBinRawURL)
  httpPage.readLine()
  local httpVerNum = tonumber(httpPage.readLine())
  local pPath, pName = getRunningPath(runPath)
  local h = fs.open(pPath..pName,"r")
  h.readLine()
  local myVersionNum = tonumber(h.readLine())
  h.close()
  if myVersionNum == httpVerNum then
    print("Everything up to date! On version, v"..tostring(myVersionNum))
  else
    print("Needs an update! Newest version is, v"..tostring(httpVerNum))
    print("You're on version, v"..tostring(myVersionNum))
    updater(pasteBinRawURL,runPath)
  end
end
--Runs all the above functions, and checks for extra/optional arguments.
function checkUpdate(pasteBinID,runPath,optionalArg)
  --Converts pastebin file ID to pastebin raw url for other functions
  local pasteBinRawURL = ("http://pastebin.com/raw.php?i="..pasteBinID)
  if optionalArg == "forceUpdate" then
    print("Forcing an update.")
    updater(pasteBinRawURL,runPath)
  elseif optionalArg == "noUpdate" then
    print("Skipping updating process...")
  else
    print("Checking if in need of an update...")
    verCheck(pasteBinRawURL,runPath)
  end
end