To find out about a device that udev created, run the following command:

(this is for /dev/input/event1, which should be a usb mouse)
udevinfo -p `udevinfo -q path -n /dev/input/event1` -a

udevinfo starts with the device the node belongs to and then walks up the
device chain, to print for every device found, all possibly useful attributes
in the udev key format.
Only attributes within one device section may be used together in one rule,
to match the device for which the node will be created.

device '/sys/class/input/event1' has major:minor 13:65
  looking at class device '/sys/class/input/event1':
    SYSFS{dev}="13:65"

follow the class device's "device"
  looking at the device chain at '/sys/devices/pci0000:00/0000:00:1d.1/usb2/2-2/2-2:1.0':
    BUS="usb"
    ID="2-2:1.0"
    SYSFS{bAlternateSetting}=" 0"
    SYSFS{bInterfaceClass}="03"
    SYSFS{bInterfaceNumber}="00"
    SYSFS{bInterfaceProtocol}="02"
    SYSFS{bInterfaceSubClass}="01"
    SYSFS{bNumEndpoints}="01"
    SYSFS{detach_state}="0"

  looking at the device chain at '/sys/devices/pci0000:00/0000:00:1d.1/usb2/2-2':
    BUS="usb"
    ID="2-2"
    SYSFS{bConfigurationValue}="1"
    SYSFS{bDeviceClass}="00"
    SYSFS{bDeviceProtocol}="00"
    SYSFS{bDeviceSubClass}="00"
    SYSFS{bMaxPower}="100mA"
    SYSFS{bNumConfigurations}="1"
    SYSFS{bNumInterfaces}=" 1"
    SYSFS{bcdDevice}="0300"
    SYSFS{bmAttributes}="a0"
    SYSFS{detach_state}="0"
    SYSFS{devnum}="8"
    SYSFS{idProduct}="0040"
    SYSFS{idVendor}="045e"
    SYSFS{manufacturer}="Microsoft"
    SYSFS{maxchild}="0"
    SYSFS{product}="Microsoft 3-Button Mouse with IntelliEye(TM)"
    SYSFS{speed}="1.5"
    SYSFS{version}=" 1.10"

  looking at the device chain at '/sys/devices/pci0000:00/0000:00:1d.1/usb2':
    BUS="usb"
    ID="usb2"
    SYSFS{bConfigurationValue}="1"
    SYSFS{bDeviceClass}="09"
    SYSFS{bDeviceProtocol}="00"
    SYSFS{bDeviceSubClass}="00"
    SYSFS{bMaxPower}="  0mA"
    SYSFS{bNumConfigurations}="1"
    SYSFS{bNumInterfaces}=" 1"
    SYSFS{bcdDevice}="0206"
    SYSFS{bmAttributes}="c0"
    SYSFS{detach_state}="0"
    SYSFS{devnum}="1"
    SYSFS{idProduct}="0000"
    SYSFS{idVendor}="0000"
    SYSFS{manufacturer}="Linux 2.6.10-1-686 uhci_hcd"
    SYSFS{maxchild}="2"
    SYSFS{product}="Intel Corp. 82801DB/DBL/DBM (ICH4/ICH4-L/ICH4-M) USB UHCI Controller #2"
    SYSFS{serial}="0000:00:1d.1"
    SYSFS{speed}="12"
    SYSFS{version}=" 1.10"

  looking at the device chain at '/sys/devices/pci0000:00/0000:00:1d.1':
    BUS="pci"
    ID="0000:00:1d.1"
    SYSFS{class}="0x0c0300"
    SYSFS{detach_state}="0"
    SYSFS{device}="0x24c4"
    SYSFS{irq}="201"
    SYSFS{local_cpus}="1"
    SYSFS{subsystem_device}="0x9020"
    SYSFS{subsystem_vendor}="0x1584"
    SYSFS{vendor}="0x8086"

  looking at the device chain at '/sys/devices/pci0000:00':
    BUS=""
    ID="pci0000:00"
    SYSFS{detach_state}="0"
Topic revision: r1 - 24 Feb 2005, JeffreyHorner
 

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