bluetoothctl [1] is the main command for configuring Bluetooth devices on Linux. Contrary to what the name's structure might lead you to expect, bluetoothctl is not part of systemd, but rather a simple set of options for setting up Bluetooth devices.

As you probably know, the Bluetooth standard is a collection of protocols for exchanging data over short distances – typically, less than five meters. Named for the 10th-century king Harald Bluetooth, who unified Denmark under the banner of Christianity, Bluetooth was developed by the Swedish company Ericsson, largely under the direction of Sven Mattisson. It was first released in 1998 and is now developed by the Bluetooth Special Interest Group [2]. Since 2005, it has been fully supported by Linux, and it has been included in the kernel since 2001. Today, the Linux implementation of Bluetooth is maintained by the BlueZ project[3]. bluetoothctl is part of the bluez-utilities package.

Bluetooth took several years to establish itself, but today, it can be used to add to your system almost every type of hardware, including speakers, printers, hard drives, keyboards, and mouses. The rise of the Internet of Things (IoT) has given the standard an enormous boost, because not only is Bluetooth's short range a security feature in itself, but the latest versions of the standard – version 5.0 as of mid-2016, although most available hardware uses version 4.0-4.2 – have exactly the built-in security features that companies are starting to realize are required by the IoT. Bluetooth smart light bulbs are already available, and more Bluetooth IoT devices are scheduled to follow.

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