title: Read/parse streamed output from BTMON in native bash?
body: <p>I'm attempting to parse stream output from <code>btmon</code> in realtime. An <code>lescan</code> process is running in the background: <code>sudo hcitool lescan &amp;</code>.</p>
  
  <p>After substantial testing, I'm at a loss for words because the following script, <strong>when executed by root</strong> in a first session:</p>
  
  <pre><code>while read -r line; do
  echo "$line"
  done &lt; &lt;(btmon 2&gt;&amp;1)
  </code></pre>
  
  <p>Does not print the same lines as: </p>
  
  <p><code>sudo btmon 2&gt;&amp;1</code></p>
  
  <p>When executed from a separate shell session. Fewer lines are printed from the first and output lags by sometimes minutes. </p>
  
  <p>What is going on? Any input or advice? </p>
  
  <hr>
  
  <p>EDIT: Example output. All three sessions are simultaneous and the expected result is identical output. All were stopped at the same time. </p>
  
  <p><code>sudo hcitool lescan</code></p>
  
  <pre><code>LE Scan ...
  49:D3:E5:61:AE:36 (unknown)
  49:D3:E5:61:AE:36 (unknown)
  28:39:5E:49:DB:23 (unknown)
  28:39:5E:49:DB:23 [TV] Samsung 9 Series (65)
  5D:C2:ED:93:59:1F (unknown)
  6A:46:64:F2:25:57 (unknown)
  6A:46:64:F2:25:57 (unknown)
  78:D0:8A:A5:8B:43 (unknown)
  78:D0:8A:A5:8B:43 (unknown)
  33:CA:22:86:F5:4D (unknown)
  C8:69:CD:6A:89:2A (unknown)
  6A:4E:F6:F6:BB:8C (unknown)
  6A:4E:F6:F6:BB:8C (unknown)
  C8:69:CD:6A:89:2A (unknown)
  5D:C2:ED:93:59:1F (unknown)
  7C:D1:C3:DA:91:14 (unknown)
  7C:D1:C3:DA:91:14 (unknown)
  6D:D2:11:18:37:F1 (unknown)
  6D:D2:11:18:37:F1 (unknown)
  F8:77:B8:8A:01:C1 (unknown)
  FF:FF:C0:22:6B:36 (unknown)
  </code></pre>
  
  <p><code>sudo btmon 2&gt;&amp;1</code></p>
  
  <pre><code>Bluetooth monitor ver 5.43
  = Note: Linux version 4.14.71+ (armv6l)                                                                      0.563610
  = Note: Bluetooth subsystem version 2.22                                                                     0.563625
  = New Index: B8:27:EB:C8:9E:A6 (Primary,UART,hci0)                                                    [hci0] 0.563632
  = Open Index: B8:27:EB:C8:9E:A6                                                                       [hci0] 0.563634
  = Index Info: B8:27:EB:C8:9E:A6 (Broadcom Corporation)                                                [hci0] 0.563638
  @ MGMT Open: bluetoothd (privileged) version 1.14                                                   {0x0001} 0.563644
  @ MGMT Open: btmon (privileged) version 1.14                                                        {0x0002} 0.563788
  @ MGMT Open: btmon (privileged) version 1.14                                                        {0x0003} 2.149663
  @ RAW Open: hcitool (privileged) version 2.22                                                      {0x0004} 11.269034
  @ RAW Close: hcitool                                                                               {0x0004} 11.270311
  @ RAW Open: hcitool (privileged) version 2.22                                               {0x0004} [hci0] 11.271277
  &lt; HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7                                           [hci0] 11.272202
          Type: Active (0x01)
          Interval: 10.000 msec (0x0010)
          Window: 10.000 msec (0x0010)
          Own address type: Public (0x00)
          Filter policy: Accept all advertisement (0x00)
  &gt; HCI Event: Command Complete (0x0e) plen 4                                                          [hci0] 11.272708
        LE Set Scan Parameters (0x08|0x000b) ncmd 1
          Status: Success (0x00)
  &lt; HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2                                               [hci0] 11.275396
          Scanning: Enabled (0x01)
          Filter duplicates: Enabled (0x01)
  &gt; HCI Event: Command Complete (0x0e) plen 4                                                          [hci0] 11.276126
        LE Set Scan Enable (0x08|0x000c) ncmd 1
          Status: Success (0x00)
  &gt; HCI Event: LE Meta Event (0x3e) plen 35                                                            [hci0] 11.287680
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Connectable undirected - ADV_IND (0x00)
          Address type: Random (0x01)
          Address: 49:D3:E5:61:AE:36 (Resolvable)
          Data length: 23
          Flags: 0x06
            LE General Discoverable Mode
            BR/EDR Not Supported
          Company: Apple, Inc. (76)
            Type: Unknown (12)
            Data: 0063169caf541000a9cd5d9975f7
          RSSI: -86 dBm (0xaa)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                                                            [hci0] 11.288789
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Scan response - SCAN_RSP (0x04)
          Address type: Random (0x01)
          Address: 49:D3:E5:61:AE:36 (Resolvable)
          Data length: 0
          RSSI: -85 dBm (0xab)
  &gt; HCI Event: LE Meta Event (0x3e) plen 43                                                            [hci0] 11.301135
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Connectable undirected - ADV_IND (0x00)
          Address type: Public (0x00)
          Address: 28:39:5E:49:DB:23 (OUI 28-39-5E)
          Data length: 31
          Flags: 0x1a
            LE General Discoverable Mode
            Simultaneous LE and BR/EDR (Controller)
            Simultaneous LE and BR/EDR (Host)
          Company: Samsung Electronics Co. Ltd. (117)
            Data: 420401017e28395e49db232a395e49db2201000000000000
          RSSI: -71 dBm (0xb9)
  &gt; HCI Event: LE Meta Event (0x3e) plen 40                                                            [hci0] 11.305925
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Scan response - SCAN_RSP (0x04)
          Address type: Public (0x00)
          Address: 28:39:5E:49:DB:23 (OUI 28-39-5E)
          Data length: 28
          Name (short): [TV] Samsung 9 Series (65)
          RSSI: -72 dBm (0xb8)
  &gt; HCI Event: LE Meta Event (0x3e) plen 26                                                            [hci0] 11.311464
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Connectable undirected - ADV_IND (0x00)
          Address type: Random (0x01)
          Address: 5D:C2:ED:93:59:1F (Resolvable)
          Data length: 14
          Flags: 0x1a
            LE General Discoverable Mode
            Simultaneous LE and BR/EDR (Controller)
            Simultaneous LE and BR/EDR (Host)
          Company: Apple, Inc. (76)
            Type: Unknown (16)
            Data: 071c6824b9
          RSSI: -92 dBm (0xa4)
  &gt; HCI Event: LE Meta Event (0x3e) plen 34                                                            [hci0] 11.329588
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Connectable undirected - ADV_IND (0x00)
          Address type: Random (0x01)
          Address: 6A:46:64:F2:25:57 (Resolvable)
          Data length: 22
          Flags: 0x1a
            LE General Discoverable Mode
            Simultaneous LE and BR/EDR (Controller)
            Simultaneous LE and BR/EDR (Host)
          Company: Apple, Inc. (76)
            Type: Unknown (14)
            Data: 01004f000702
            Type: Unknown (16)
            Data: 0a1cca57b2
          RSSI: -77 dBm (0xb3)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                                                            [hci0] 11.332246
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Scan response - SCAN_RSP (0x04)
          Address type: Random (0x01)
          Address: 6A:46:64:F2:25:57 (Resolvable)
          Data length: 0
          RSSI: -77 dBm (0xb3)
  &gt; HCI Event: LE Meta Event (0x3e) plen 26                                                            [hci0] 11.373918
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Connectable undirected - ADV_IND (0x00)
          Address type: Random (0x01)
          Address: 78:D0:8A:A5:8B:43 (Resolvable)
          Data length: 14
          Flags: 0x1a
            LE General Discoverable Mode
            Simultaneous LE and BR/EDR (Controller)
            Simultaneous LE and BR/EDR (Host)
          Company: Apple, Inc. (76)
            Type: Unknown (16)
            Data: 031c429af9
          RSSI: -88 dBm (0xa8)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                                                            [hci0] 11.376067
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Scan response - SCAN_RSP (0x04)
          Address type: Random (0x01)
          Address: 78:D0:8A:A5:8B:43 (Resolvable)
          Data length: 0
          RSSI: -87 dBm (0xa9)
  &gt; HCI Event: LE Meta Event (0x3e) plen 27                                                            [hci0] 11.385151
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Non connectable undirected - ADV_NONCONN_IND (0x03)
          Address type: Random (0x01)
          Address: 33:CA:22:86:F5:4D (Non-Resolvable)
          Data length: 15
          Flags: 0x1b
            LE Limited Discoverable Mode
            LE General Discoverable Mode
            Simultaneous LE and BR/EDR (Controller)
            Simultaneous LE and BR/EDR (Host)
          Company: Apple, Inc. (76)
            Type: Apple TV (9)
            Data: 032bc0a8012b
          RSSI: -68 dBm (0xbc)
  &gt; HCI Event: LE Meta Event (0x3e) plen 23                                                            [hci0] 11.400609
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Connectable undirected - ADV_IND (0x00)
          Address type: Public (0x00)
          Address: C8:69:CD:6A:89:2A (Apple, Inc.)
          Data length: 11
          Flags: 0x1a
            LE General Discoverable Mode
            Simultaneous LE and BR/EDR (Controller)
            Simultaneous LE and BR/EDR (Host)
          Company: Apple, Inc. (76)
            Type: Unknown (16)
            Data: 0104
          RSSI: -80 dBm (0xb0)
  &gt; HCI Event: LE Meta Event (0x3e) plen 32                                                            [hci0] 11.486780
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Connectable undirected - ADV_IND (0x00)
          Address type: Random (0x01)
          Address: 6A:4E:F6:F6:BB:8C (Resolvable)
          Data length: 20
          Flags: 0x1a
            LE General Discoverable Mode
            Simultaneous LE and BR/EDR (Controller)
            Simultaneous LE and BR/EDR (Host)
          Company: Apple, Inc. (76)
            Type: Unknown (13)
            Data: 53d559a3
            Type: Unknown (16)
            Data: 031cf2b2a6
          RSSI: -85 dBm (0xab)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                                                            [hci0] 11.489229
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Scan response - SCAN_RSP (0x04)
          Address type: Random (0x01)
          Address: 6A:4E:F6:F6:BB:8C (Resolvable)
          Data length: 0
          RSSI: -87 dBm (0xa9)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                                                            [hci0] 11.585662
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Scan response - SCAN_RSP (0x04)
          Address type: Public (0x00)
          Address: C8:69:CD:6A:89:2A (Apple, Inc.)
          Data length: 0
          RSSI: -82 dBm (0xae)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                                                            [hci0] 11.855660
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Scan response - SCAN_RSP (0x04)
          Address type: Random (0x01)
          Address: 5D:C2:ED:93:59:1F (Resolvable)
          Data length: 0
          RSSI: -90 dBm (0xa6)
  &gt; HCI Event: LE Meta Event (0x3e) plen 23                                                            [hci0] 11.999393
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Connectable undirected - ADV_IND (0x00)
          Address type: Public (0x00)
          Address: 7C:D1:C3:DA:91:14 (Apple, Inc.)
          Data length: 11
          Flags: 0x06
            LE General Discoverable Mode
            BR/EDR Not Supported
          Company: Apple, Inc. (76)
            Type: Unknown (16)
            Data: 0b08
          RSSI: -97 dBm (0x9f)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                                                            [hci0] 12.191914
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Scan response - SCAN_RSP (0x04)
          Address type: Public (0x00)
          Address: 7C:D1:C3:DA:91:14 (Apple, Inc.)
          Data length: 0
          RSSI: -87 dBm (0xa9)
  &gt; HCI Event: LE Meta Event (0x3e) plen 26                                                            [hci0] 12.772156
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Connectable undirected - ADV_IND (0x00)
          Address type: Random (0x01)
          Address: 6D:D2:11:18:37:F1 (Resolvable)
          Data length: 14
          Flags: 0x1a
            LE General Discoverable Mode
            Simultaneous LE and BR/EDR (Controller)
            Simultaneous LE and BR/EDR (Host)
          Company: Apple, Inc. (76)
            Type: Unknown (16)
            Data: 0198b24d86
          RSSI: -80 dBm (0xb0)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                                                            [hci0] 12.773961
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Scan response - SCAN_RSP (0x04)
          Address type: Random (0x01)
          Address: 6D:D2:11:18:37:F1 (Resolvable)
          Data length: 0
          RSSI: -80 dBm (0xb0)
  &gt; HCI Event: LE Meta Event (0x3e) plen 40                                                            [hci0] 13.347879
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Non connectable undirected - ADV_NONCONN_IND (0x03)
          Address type: Public (0x00)
          Address: F8:77:B8:8A:01:C1 (Samsung Electronics Co.,Ltd)
          Data length: 28
          Company: Samsung Electronics Co. Ltd. (117)
            Data: 4204018060f877b88a01c1fa77b88a01c001000000000000
          RSSI: -100 dBm (0x9c)
  &gt; HCI Event: LE Meta Event (0x3e) plen 26                                                            [hci0] 14.016707
        LE Advertising Report (0x02)
          Num reports: 1
          Event type: Connectable undirected - ADV_IND (0x00)
          Address type: Public (0x00)
          Address: FF:FF:C0:22:6B:36 (OUI FF-FF-C0)
          Data length: 14
          Flags: 0x05
            LE Limited Discoverable Mode
            BR/EDR Not Supported
          TX power: 0 dBm
          Appearance: Keyboard (0x03c1)
          16-bit Service UUIDs (partial): 1 entry
            Unknown (0xffe0)
          RSSI: -90 dBm (0xa6)
  </code></pre>
  
  <p>And, finally, the script:</p>
  
  <pre><code>Bluetooth monitor ver 5.43
  = Note: Linux version 4.14.71+ (armv6l)                                0.149535
  = Note: Bluetooth subsystem version 2.22                               0.149551
  = New Index: B8:27:EB:C8:9E:A6 (Primary,UART,hci0)              [hci0] 0.149556
  = Open Index: B8:27:EB:C8:9E:A6                                 [hci0] 0.149559
  = Index Info: B8:27:EB:C8:9E:A6 (Broadcom Corporation)          [hci0] 0.149563
  @ MGMT Open: btmon (privileged) version 1.14                  {0x0002} 0.149569
  @ MGMT Open: bluetoothd (privileged) version 1.14             {0x0001} 0.149573
  @ MGMT Open: btmon (privileged) version 1.14                  {0x0003} 0.149663
  @ RAW Open: hcitool (privileged) version 2.22                 {0x0004} 9.269034
  @ RAW Close: hcitool                                          {0x0004} 9.270311
  @ RAW Open: hcitool (privileged) version 2.22          {0x0004} [hci0] 9.271277
  &lt; HCI Command: LE Set Scan Parameters (0x08|0x000b) plen 7      [hci0] 9.272202
  Type: Active (0x01)
  Interval: 10.000 msec (0x0010)
  Window: 10.000 msec (0x0010)
  Own address type: Public (0x00)
  Filter policy: Accept all advertisement (0x00)
  &gt; HCI Event: Command Complete (0x0e) plen 4                     [hci0] 9.272708
  LE Set Scan Parameters (0x08|0x000b) ncmd 1
  Status: Success (0x00)
  &lt; HCI Command: LE Set Scan Enable (0x08|0x000c) plen 2          [hci0] 9.275396
  Scanning: Enabled (0x01)
  Filter duplicates: Enabled (0x01)
  &gt; HCI Event: Command Complete (0x0e) plen 4                     [hci0] 9.276126
  LE Set Scan Enable (0x08|0x000c) ncmd 1
  Status: Success (0x00)
  &gt; HCI Event: LE Meta Event (0x3e) plen 35                       [hci0] 9.287680
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Connectable undirected - ADV_IND (0x00)
  Address type: Random (0x01)
  Address: 49:D3:E5:61:AE:36 (Resolvable)
  Data length: 23
  Flags: 0x06
  LE General Discoverable Mode
  BR/EDR Not Supported
  Company: Apple, Inc. (76)
  Type: Unknown (12)
  Data: 0063169caf541000a9cd5d9975f7
  RSSI: -86 dBm (0xaa)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                       [hci0] 9.288789
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Scan response - SCAN_RSP (0x04)
  Address type: Random (0x01)
  Address: 49:D3:E5:61:AE:36 (Resolvable)
  Data length: 0
  RSSI: -85 dBm (0xab)
  &gt; HCI Event: LE Meta Event (0x3e) plen 43                       [hci0] 9.301135
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Connectable undirected - ADV_IND (0x00)
  Address type: Public (0x00)
  Address: 28:39:5E:49:DB:23 (OUI 28-39-5E)
  Data length: 31
  Flags: 0x1a
  LE General Discoverable Mode
  Simultaneous LE and BR/EDR (Controller)
  Simultaneous LE and BR/EDR (Host)
  Company: Samsung Electronics Co. Ltd. (117)
  Data: 420401017e28395e49db232a395e49db2201000000000000
  RSSI: -71 dBm (0xb9)
  &gt; HCI Event: LE Meta Event (0x3e) plen 40                       [hci0] 9.305925
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Scan response - SCAN_RSP (0x04)
  Address type: Public (0x00)
  Address: 28:39:5E:49:DB:23 (OUI 28-39-5E)
  Data length: 28
  Name (short): [TV] Samsung 9 Series (65)
  RSSI: -72 dBm (0xb8)
  &gt; HCI Event: LE Meta Event (0x3e) plen 26                       [hci0] 9.311464
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Connectable undirected - ADV_IND (0x00)
  Address type: Random (0x01)
  Address: 5D:C2:ED:93:59:1F (Resolvable)
  Data length: 14
  Flags: 0x1a
  LE General Discoverable Mode
  Simultaneous LE and BR/EDR (Controller)
  Simultaneous LE and BR/EDR (Host)
  Company: Apple, Inc. (76)
  Type: Unknown (16)
  Data: 071c6824b9
  RSSI: -92 dBm (0xa4)
  &gt; HCI Event: LE Meta Event (0x3e) plen 34                       [hci0] 9.329588
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Connectable undirected - ADV_IND (0x00)
  Address type: Random (0x01)
  Address: 6A:46:64:F2:25:57 (Resolvable)
  Data length: 22
  Flags: 0x1a
  LE General Discoverable Mode
  Simultaneous LE and BR/EDR (Controller)
  Simultaneous LE and BR/EDR (Host)
  Company: Apple, Inc. (76)
  Type: Unknown (14)
  Data: 01004f000702
  Type: Unknown (16)
  Data: 0a1cca57b2
  RSSI: -77 dBm (0xb3)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                       [hci0] 9.332246
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Scan response - SCAN_RSP (0x04)
  Address type: Random (0x01)
  Address: 6A:46:64:F2:25:57 (Resolvable)
  Data length: 0
  RSSI: -77 dBm (0xb3)
  &gt; HCI Event: LE Meta Event (0x3e) plen 26                       [hci0] 9.373918
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Connectable undirected - ADV_IND (0x00)
  Address type: Random (0x01)
  Address: 78:D0:8A:A5:8B:43 (Resolvable)
  Data length: 14
  Flags: 0x1a
  LE General Discoverable Mode
  Simultaneous LE and BR/EDR (Controller)
  Simultaneous LE and BR/EDR (Host)
  Company: Apple, Inc. (76)
  Type: Unknown (16)
  Data: 031c429af9
  RSSI: -88 dBm (0xa8)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                       [hci0] 9.376067
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Scan response - SCAN_RSP (0x04)
  Address type: Random (0x01)
  Address: 78:D0:8A:A5:8B:43 (Resolvable)
  Data length: 0
  RSSI: -87 dBm (0xa9)
  &gt; HCI Event: LE Meta Event (0x3e) plen 27                       [hci0] 9.385151
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Non connectable undirected - ADV_NONCONN_IND (0x03)
  Address type: Random (0x01)
  Address: 33:CA:22:86:F5:4D (Non-Resolvable)
  Data length: 15
  Flags: 0x1b
  LE Limited Discoverable Mode
  LE General Discoverable Mode
  Simultaneous LE and BR/EDR (Controller)
  Simultaneous LE and BR/EDR (Host)
  Company: Apple, Inc. (76)
  Type: Apple TV (9)
  Data: 032bc0a8012b
  RSSI: -68 dBm (0xbc)
  &gt; HCI Event: LE Meta Event (0x3e) plen 23                       [hci0] 9.400609
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Connectable undirected - ADV_IND (0x00)
  Address type: Public (0x00)
  Address: C8:69:CD:6A:89:2A (Apple, Inc.)
  Data length: 11
  Flags: 0x1a
  LE General Discoverable Mode
  Simultaneous LE and BR/EDR (Controller)
  Simultaneous LE and BR/EDR (Host)
  Company: Apple, Inc. (76)
  Type: Unknown (16)
  Data: 0104
  RSSI: -80 dBm (0xb0)
  &gt; HCI Event: LE Meta Event (0x3e) plen 32                       [hci0] 9.486780
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Connectable undirected - ADV_IND (0x00)
  Address type: Random (0x01)
  Address: 6A:4E:F6:F6:BB:8C (Resolvable)
  Data length: 20
  Flags: 0x1a
  LE General Discoverable Mode
  Simultaneous LE and BR/EDR (Controller)
  Simultaneous LE and BR/EDR (Host)
  Company: Apple, Inc. (76)
  Type: Unknown (13)
  Data: 53d559a3
  Type: Unknown (16)
  Data: 031cf2b2a6
  RSSI: -85 dBm (0xab)
  &gt; HCI Event: LE Meta Event (0x3e) plen 12                       [hci0] 9.489229
  LE Advertising Report (0x02)
  Num reports: 1
  Event type: Scan response - SCAN_RSP (0x04)
  Address type: Random (0x01)
  Address: 6A:4E:F6:F6:BB:8C (Resolvable)
  Data length: 0
  RSSI: -87 dBm (0xa9)
  </code></pre>
  
  <p>As shown, the script is lagging substantially. If I wait until the <code>hcitool</code> settles down, the script does not catch up. Output just ... stops. </p>
  
  <p>I'm baffled. </p>