TrackerMonitorV1

function extract(s)
  local t = {}
  local name, armor, account, health, world, x, y, z
  local a = 0
  local b = 0
  while (true) do
    a, b, name, armor, account, health, z, y, world, x = string.find(s, "\"sort\":0,\"name\":\"([^\"]+)\",\"armor\":(%d+),\"account\":\"([^\"]+)\",\"health\":(%d+),\"type\":\"player\",\"z\":([-0-9.]+),\"y\":([-0-9.]+),\"world\":\"([^\"]+)\",\"x\":([-0-9.]+)", b + 1)
    if (a == nil) then
      break
    end
    t[account] = {}
    t[account].armor = tonumber(armor)
    t[account].name = name
    t[account].health = tonumber(health)
    t[account].world = world
    t[account].loc = vector.new(tonumber(x), tonumber(y), tonumber(z))
    local offset = here - t[account].loc
    t[account].dist = math.floor(math.sqrt(offset.x * offset.x + offset.z * offset.z))
  end
  return t
end

function getDisplay()
  local plist = peripheral.getNames()
  local i, name
  for i, name in pairs(plist) do
    if peripheral.getType(name) == "monitor" then
      return peripheral.wrap(name)
    end
  end
  return term
end

fh = http.get("http://tekkit.craftersland.net:25800/up/world/world/111")
txt = fh.readAll()
fh.close()
_,_,ts = string.find(txt, "{\"timestamp\":(%d+).")

print ("Starting timestamp: ", ts)
here = vector.new(-325, 80, -2538)
mon = getDisplay()
-- mon.setTextScale(0.8)
cols, rows = mon.getSize()
players = {}
while (true) do
  fh = http.get("http://tekkit.craftersland.net:25800/up/world/world/" .. ts)
  if (fh) then
    txt = fh.readAll()
    fh.close()
    _,_,ts = string.find(txt, "{\"timestamp\":(%d+),")
    if (ts) then
      players = extract(txt)
    end
  end
  local i = 1
  st = {}
  for key in pairs(players) do
    st[#st+1] = key
  end
  table.sort(st, function(a, b) return players[a].dist < players[b].dist end)
  mon.clear()
  for k = 1, #st do
    account = st[k]
    if (players[account].world == "world") then
      mon.setCursorPos(1, i)
      mon.write(account.." - "..players[account].dist)
      -- mon.write(account.." - "..math.floor(players[account].loc.x).." "..math.floor(players[account].loc.y).." "..math.floor(players[account].loc.z).." - armor "..players[account].armor.." - health "..players[account].health.." - distance "..players[account].dist.." - "..players[account].world)
      i = i + 1
    end
  end

  os.sleep(5.0)
end