Sensor

function d(x,y,z)
  return math.sqrt(x*x+y*y+z*z)
end

p=peripheral.wrap("right")
function scan ()
  names=p.getPlayerNames()
  if names ~= nil then
    for key,name in pairs(names) do
      data=p.getPlayerData(name)
      pos=data.position
      health=data.health
      heldItem=data.heldItem.name
      dist=d(pos.x,pos.y,pos.z)
      print(name," ","Distance = ",math.floor(dist))
      print("Health = ",health)
      print("HeldItem = ",heldItem)
    end
  end
end
while true do
  pcall(scan)
  sleep(4)
end