Pastecraft Server

-- The location of the pastes
pasteFolder = "disk/paste/"

function LOG (str)
    print(str)
    fichier = pasteFolder .. "log"
    if (not fs.exists(fichier)) then
        file = fs.open(fichier, "w")
        file.writeLine("-- CREATING FILE --")
        file.close()
    end
    file = fs.open(fichier, "a")
    file.writeLine("> " .. tostring(os.getComputerID()) .. " : " ..str)
    file.close()
end

function split (str)
  t = {} ; i = 1
  for st in string.gmatch(str, "([^=]+)") do
    t[i] = st
    i = i + 1
  end
  return t
end

function startsWith(self, piece)
  return string.sub(self, 1, string.len(piece)) == piece
end


function getChar (a, b)
  return string.char(math.random(a, b))
end

function getFileName ()
  str = ""
  for i = 1, 6 do
   rand = math.random (1, 3)
   if rand == 1 then
      str = str .. getChar (48, 57)
   elseif rand == 2 then
      str = str .. getChar(65, 90)
   else
      str = str..getChar(97, 122)
   end
  end
  return str
end

function getFile()
  str = getFileName()
  while (fs.exists(pasteFolder .. tostring(str))) do
    print ("File " .. str .. " already exists. Generating new name...")
    str = getFileName()
  end
  return str
end

if (not fs.exists(pasteFolder)) then
    fs.makeDir(pasteFolder)
end

LOG("Starting up Pastecraft server on id " .. tostring(os.getComputerID()) .. " ...")
rednet.open("back")
while true do

    local e, id, text = os.pullEvent("rednet_message")
    if (startsWith(text, "get")) then
        pasteID = split(text)[2]
        if (fs.exists(pasteFolder .. pasteID)) then
            fichierLu = fs.open(pasteFolder..pasteID, "r")
            toSend = textutils.serialize(fichierLu.readAll())
            fichierLu.close()
            rednet.send(id, "get=" .. toSend)
            LOG("GET : " .. pasteID .. " by " .. tostring (id))
        else
            rednet.send(id, "404")
            LOG("GET : NIL by " .. tostring (id) .. " (fail)")
        end
    elseif (startsWith(text, "put")) then
        paste = textutils.unserialize(split(text)[2])
        fileName = getFile()
        fichierPaste = fs.open(pasteFolder .. fileName, "w")
        fichierPaste.write(paste)
        fichierPaste.close()
        rednet.send(id, "put=" .. fileName)
        LOG("PUT : " .. fileName .. " by " .. tostring(id))
    else
        rednet.send(id, "UNKNOWN FUNCTION")
    end
end