OC remote FS

function split(text, delimiter)
  local result = {}
  delimiter = delimiter or " "
  string.gsub(text, "([^"..delimiter.."]+)", function(match) table.insert(result, match) end)
  return result
end

local term = require "term"
function print(...)
  term.write(table.concat({...}))
  term.write("\n")
end

local component = require "component"
if (not component.isAvailable("internet")) then
  print("No internet card found.")
  return false
elseif (not component.internet.isTcpEnabled()) then
  print("TCP connections are forbidden by config settings.")
  return false
end

local host, port = ...
host = host or "78.34.84.168" -- DEBUG: remove!
if (not host) then
  print("Usage: remotefs <host> [<port>]")
  return false
end
port = tonumber(port) or 3425

local computer = require "computer"
local internet = component.internet
local handle = internet.connect(host..":"..port) -- OC BUG #533 needs to be in this format
if (not handle) then
  print("Failed to connect.")
  return false
end
while not internet.finishConnect(handle) do os.sleep(0.1) end-- OC BUG #535 takes some time

function write(content)
  local bytesToWrite = #content
  local bytesWritten
  while (bytesToWrite > 0) do
    bytesWritten = internet.write(handle, content)
    if (bytesWritten > 0) then
      bytesToWrite = bytesToWrite - bytesWritten
      if (bytesToWrite > 0) then
        content = string.sub(content, bytesWritten + 1)
      end
    end
  end
end

function writeln(content)
  internet.write(handle, content)
  internet.write(handle, "\n")
end

function read()
  if (#readbuffer > 0) then
print("read from buffer")
    local result = readbuffer
    readbuffer = ""
    return result
  else
print("read from stream")
    return internet.read(handle)
  end
end

local readbuffer = ""
function readln()
print("readln")
  local chunk
  local s, e = string.find(readbuffer, "\n", 1, true)
  while (not s) do
    chunk = internet.read(handle)
    if (chunk) then
      readbuffer = readbuffer .. chunk
if (#readbuffer > 0) then print("readln: ", readbuffer) end
    else
      terminate()
      return false
    end
    s, e = string.find(readbuffer, "\n", 1, true)
  end
print("readln complete: ", string.sub(readbuffer, 1, s - 1))
  local line = string.sub(readbuffer, 1, s - 1)
  if (#readbuffer > s) then
    readbuffer = string.sub(readbuffer, s + 1)
  else
    readbuffer = ""
  end
  return line
end

function terminate()
print("terminate")
  running = false
  if (handle) then
    internet.close(handle)
    handle = nil
  end
end

function request(content)
print("request: ", content)
  writeln(content)
  return readln()
end

function requestOk(content)
  local result = request(content)
  if (not result) then
    return false
  else
    return ("OK" == string.upper(result))
  end
end

local computer = require "computer"
if (not requestOk("remotefs 1 "..computer.address())) then
  print("Server denied login.")
  terminate()
  return false
end

local fs = require "filesystem"

local COMMANDS = setmetatable({}, {__index = function(t, v) writeln("NO") print("Received unknown command: ", v) end})

function COMMANDS.list(dir)
print("LIST ", dir)
  if (not fs.isDirectory(dir)) then
    writeln("NO")
    return false
  end
  local response = {}
  local filename
  for file in fs.list(dir) do
    if ((file ~= ".") and (#file > 0)) then
      filename = fs.canonical(dir..file)
      if (string.sub(filename, 1, 4) ~= "/mnt") then -- this would cause some flooding and recursion
        if ((string.sub(filename, -1) ~= "/") and fs.isDirectory(filename)) then
          filename = filename .. "/"
        end
        table.insert(response, filename..":"..fs.lastModified(file))
      end
    end
  end
  response = table.concat(response, " ")
  writeln(response)
print("LIST wrote ", response)
  return true
end

function COMMANDS.get(filename)
print("GET ", filename)
  local file = io.open(filename, "rb")
  if (not file) then
    writeln("NO")
    return false
  end
  local content = file:read("*a")
  file:close()
  writeln("PUT "..filename.." "..tostring(#content))
  write(content)
  return true
end

function COMMANDS.put(filename, size)
print("PUT ", filename, " ", size)
  local size = tonumber(size)
  if (not size) then
    writeln("NO")
    return false
  end
  local file = io.open(filename, "wb+")
  if (not file) then
    writeln("NO")
    return false
  end
  local content = ""
  while (#content < size) do
    content = content .. read()
  end
  if (file:write(content)) then
    writeln("OK")
  else
    writeln("NO")
  end
  file:close()
end

function executeCommand(command, ...)
print("Command: ", command, " ", ...)
  COMMANDS[string.lower(command)](...)
end

running = true

local line, s, e
while running do
  line = readln()
  if (line) then
    executeCommand(table.unpack(split(line)))
  else
    print("Server terminated connection")
    terminate()
  end
end