usb-devices

usb-devices

The `usb-devices` command is a simple utility, generally included in the `usbutils` package, used to display detailed information about USB devices currently connected to a Linux system. It parses data from the `/sys/bus/usb/devices` directory, presenting a human-readable report organized by USB device. The output includes vendor IDs, product IDs, device classes, configurations, interfaces, drivers in use, endpoints, speed, and power consumption details. This command is extremely useful for debugging USB device issues, identifying specific hardware, and understanding how the kernel has enumerated each device. It doesn't offer command-line options for filtering or formatting the output beyond what's implicitly determined by its internal structure. It's a quick way to check whether a device is properly recognized, if the correct driver is loaded, and if it's drawing the expected amount of power. Its data can be piped to other tools like `grep` to search for specific attributes.

This command relies on the data present in the `/sys/bus/usb/devices` directory. If the USB subsystem or device drivers are not functioning correctly, the information displayed by `usb-devices` may be incomplete or inaccurate. It doesn't provide any facilities for device control or modification, only information retrieval. Requires root or appropriate permissions to access sysfs data.

The output is structured hierarchically, showing USB devices (hubs and endpoints) connected to the USB bus. Each device section contains various attributes, such as vendor ID (idVendor), product ID (idProduct), and the drivers used for each interface (Driver). It is important to look at bMaxPower to understand power draw on a specific usb port.

The `usb-devices` command depends on the `usbutils` package being installed and the Linux kernel properly exporting the necessary USB device information through the `/sys` filesystem. A functional USB subsystem is crucial for this command to work correctly.

The `usb-devices` command is part of the `usbutils` package, which has been actively maintained since the early 2000s. It was developed to provide a simple way to inspect the USB device tree in Linux, complementing other tools like `lsusb` which provide a more concise overview. Its usage has grown alongside the proliferation of USB devices and the increasing complexity of USB device drivers.

lsusb(1), udevadm(8)