title: Fast Way To Check Many Bluetooth Devices by MAC Address
body: <p>I'm creating a tool that checks for the presence of many (~100) bluetooth devices.  I'll have their MAC addresses already.  I just want to know if they're in range, even if <strong>not</strong> set to discoverable.  </p>
  
  <p>Using <code>hcitool name &lt;bt_addr&gt;</code> does this.  But it's not very fast; it takes up to 5 seconds to check each address, especially if the device is not in range.  If I fork parallel subprocesses, it still takes up to 5 seconds each, as if bluez or something in the stack is serializing the requests.  </p>
  
  <p>Is there a faster way to check for the presence of BT devices by MAC address?  I don't need to know the names of them, just if they're around (whether set discoverable or not).  Ideally I'd like to check all ~100 in half a minute or less.</p>
  
  <p>Bonus points if the solution doesn't require sudo (like l2ping), but OK if that's the only way.  Platform is Ubuntu Linux, using a Cambridge Silicon BT dongle if it matters...</p>
  
  <p>Thanx,</p>
  
  <p>-- Steve</p>