udevmonitor prints the received event from the kernel [UEVENT]
and the event which udev sends out after rule processing [UDEV]

UEVENT[1147286890.618539] add@/devices/pci0000:00/0000:00:10.3/usb4/4-3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3
SUBSYSTEM=usb
SEQNUM=2621
PHYSDEVBUS=usb
PHYSDEVDRIVER=usb

UEVENT[1147286890.618641] add@/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0
SUBSYSTEM=usb
SEQNUM=2622
PHYSDEVBUS=usb
DEVICE=/proc/bus/usb/004/004
PRODUCT=13fe/1a21/100
TYPE=0/0/0
INTERFACE=8/6/80
MODALIAS=usb:v13FEp1A21d0100dc00dsc00dp00ic08isc06ip50

UEVENT[1147286890.618662] add@/class/scsi_host/host2
ACTION=add
DEVPATH=/class/scsi_host/host2
SUBSYSTEM=scsi_host
SEQNUM=2623
PHYSDEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0/host2

UEVENT[1147286890.618679] add@/class/usb_device/usbdev4.4
ACTION=add
DEVPATH=/class/usb_device/usbdev4.4
SUBSYSTEM=usb_device
SEQNUM=2624
PHYSDEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3
PHYSDEVBUS=usb
PHYSDEVDRIVER=usb
MAJOR=189
MINOR=387

UDEV  [1147286890.647577] add@/devices/pci0000:00/0000:00:10.3/usb4/4-3
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3
SUBSYSTEM=usb
SEQNUM=2621
PHYSDEVBUS=usb
PHYSDEVDRIVER=usb
UDEVD_EVENT=1

UDEV  [1147286890.756324] add@/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0
SUBSYSTEM=usb
SEQNUM=2622
PHYSDEVBUS=usb
DEVICE=/proc/bus/usb/004/004
PRODUCT=13fe/1a21/100
TYPE=0/0/0
INTERFACE=8/6/80
MODALIAS=usb:v13FEp1A21d0100dc00dsc00dp00ic08isc06ip50
UDEVD_EVENT=1

UDEV  [1147286890.783511] add@/class/scsi_host/host2
UDEV_LOG=3
ACTION=add
DEVPATH=/class/scsi_host/host2
SUBSYSTEM=scsi_host
SEQNUM=2623
PHYSDEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0/host2
UDEVD_EVENT=1

UDEV  [1147286890.866541] add@/class/usb_device/usbdev4.4
UDEV_LOG=3
ACTION=add
DEVPATH=/class/usb_device/usbdev4.4
SUBSYSTEM=usb_device
SEQNUM=2624
PHYSDEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3
PHYSDEVBUS=usb
PHYSDEVDRIVER=usb
MAJOR=189
MINOR=387
UDEVD_EVENT=1
USB_BUS=004
USB_DEV=004
DEVNAME=/dev/bus/usb/004/004

UEVENT[1147286895.617942] add@/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0/host2/target2:0:0/2:0:0:0
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0/host2/target2:0:0/2:0:0:0
SUBSYSTEM=scsi
SEQNUM=2625
PHYSDEVBUS=scsi

UEVENT[1147286895.808372] add@/block/sda
ACTION=add
DEVPATH=/block/sda
SUBSYSTEM=block
SEQNUM=2626
MINOR=0
MAJOR=8
PHYSDEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0/host2/target2:0:0/2:0:0:0
PHYSDEVBUS=scsi
PHYSDEVDRIVER=sd

UDEV  [1147286898.899495] add@/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0/host2/target2:0:0/2:0:0:0
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0/host2/target2:0:0/2:0:0:0
SUBSYSTEM=scsi
SEQNUM=2625
PHYSDEVBUS=scsi
UDEVD_EVENT=1

UDEV  [1147286898.984374] add@/block/sda
UDEV_LOG=3
ACTION=add
DEVPATH=/block/sda
SUBSYSTEM=block
SEQNUM=2626
MINOR=0
MAJOR=8
PHYSDEVPATH=/devices/pci0000:00/0000:00:10.3/usb4/4-3/4-3:1.0/host2/target2:0:0/2:0:0:0
PHYSDEVBUS=scsi
PHYSDEVDRIVER=sd
UDEVD_EVENT=1
DEVNAME=/dev/sda