Modern Linux distributions are capable of identifying a hardware component which is plugged into an already-running system. There are a lot of user-friendly distributions like Ubuntu, which will automatically run specific applications like Rhythmbox when a portable device like an iPod is plugged into the system.

Hotplugging (which is the word used to describe the process of inserting devices into a running system) is achieved in a Linux distribution by a combination of three components: Udev, HAL, and Dbus.

Udev supplies a dynamic device directory containing only the nodes for devices which are connected to the system. It creates or removes the device node files in the /dev directory as they are plugged in or taken out. Dbus is like a system bus which is used for inter-process communication. The HAL gets information from the Udev service, when a device is attached to the system and it creates an XML representation of that device. It then notifies the corresponding desktop application like Nautilus through the Dbus and Nautilus will open the mounted device’s files. Continue reading →