udevadm monitor -p
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent

KERNEL[24385.401743] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2
SUBSYSTEM=usb
DEVNAME=/dev/bus/usb/001/047
DEVTYPE=usb_device
PRODUCT=5ac/12ab/704
TYPE=0/0/0
BUSNUM=001
DEVNUM=047
SEQNUM=26250
MAJOR=189
MINOR=46

KERNEL[24385.403583] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=6/1/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00ic06isc01ip01in00
SEQNUM=26251

KERNEL[24385.403698] bind     /devices/pci0000:00/0000:00:14.0/usb1/1-2 (usb)
ACTION=bind
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2
SUBSYSTEM=usb
DEVNAME=/dev/bus/usb/001/047
DEVTYPE=usb_device
DRIVER=usb
PRODUCT=5ac/12ab/704
TYPE=0/0/0
BUSNUM=001
DEVNUM=047
SEQNUM=26252
MAJOR=189
MINOR=46

KERNEL[24385.406444] remove   /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0 (usb)
ACTION=remove
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=6/1/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00ic06isc01ip01in00
SEQNUM=26253

KERNEL[24385.409038] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=6/1/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00ic06isc01ip01in00
SEQNUM=26254

UDEV  [24385.961713] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2
SUBSYSTEM=usb
DEVNAME=/dev/bus/usb/001/047
DEVTYPE=usb_device
PRODUCT=5ac/12ab/704
TYPE=0/0/0
BUSNUM=001
DEVNUM=047
SEQNUM=26250
USEC_INITIALIZED=24385401751
USBMUX_SUPPORTED=1
ID_BUS=usb
ID_MODEL=iPad
ID_MODEL_ENC=iPad
ID_MODEL_ID=12ab
ID_SERIAL=Apple_Inc._iPad_3e4245d06e90def26aa720dfb8d05d6634aa3d00
ID_SERIAL_SHORT=3e4245d06e90def26aa720dfb8d05d6634aa3d00
ID_VENDOR=Apple_Inc.
ID_VENDOR_ENC=Apple\x20Inc.
ID_VENDOR_ID=05ac
ID_REVISION=0704
ID_USB_MODEL=iPad
ID_USB_MODEL_ENC=iPad
ID_USB_MODEL_ID=12ab
ID_USB_SERIAL=Apple_Inc._iPad_3e4245d06e90def26aa720dfb8d05d6634aa3d00
ID_USB_SERIAL_SHORT=3e4245d06e90def26aa720dfb8d05d6634aa3d00
ID_USB_VENDOR=Apple_Inc.
ID_USB_VENDOR_ENC=Apple\x20Inc.
ID_USB_VENDOR_ID=05ac
ID_USB_REVISION=0704
ID_USB_INTERFACES=:060101:010100:010200:030000:fffe02:fffd01:
ID_VENDOR_FROM_DATABASE=Apple, Inc.
ID_MODEL_FROM_DATABASE=iPad
ID_PATH_WITH_USB_REVISION=pci-0000:00:14.0-usbv2-0:2
ID_PATH=pci-0000:00:14.0-usb-0:2
ID_PATH_TAG=pci-0000_00_14_0-usb-0_2
ID_FOR_SEAT=usb-pci-0000_00_14_0-usb-0_2
DRIVER=usb
MAJOR=189
MINOR=46
TAGS=:systemd:uaccess:seat:
CURRENT_TAGS=:systemd:uaccess:seat:

UDEV  [24385.963990] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=6/1/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00ic06isc01ip01in00
SEQNUM=26251
USEC_INITIALIZED=24385405469
ID_VENDOR_FROM_DATABASE=Apple, Inc.
ID_MODEL_FROM_DATABASE=iPad
ID_PATH_WITH_USB_REVISION=pci-0000:00:14.0-usbv2-0:2:1.0
ID_PATH=pci-0000:00:14.0-usb-0:2:1.0
ID_PATH_TAG=pci-0000_00_14_0-usb-0_2_1_0

KERNEL[24386.211241] remove   /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0 (usb)
ACTION=remove
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=6/1/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00ic06isc01ip01in00
SEQNUM=26255

KERNEL[24386.215465] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.0 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=6/1/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00ic06isc01ip01in00
SEQNUM=26256

KERNEL[24386.215758] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.1 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.1
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=255/254/2
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00icFFiscFEip02in01
SEQNUM=26257

KERNEL[24386.215797] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.2 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.2
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=255/253/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00icFFiscFDip01in02
SEQNUM=26258

UDEV  [24386.217492] bind     /devices/pci0000:00/0000:00:14.0/usb1/1-2 (usb)
ACTION=bind
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2
SUBSYSTEM=usb
DEVNAME=/dev/bus/usb/001/047
DEVTYPE=usb_device
DRIVER=usb
PRODUCT=5ac/12ab/704
TYPE=0/0/0
BUSNUM=001
DEVNUM=047
SEQNUM=26252
USEC_INITIALIZED=24385401751
USBMUX_SUPPORTED=1
ID_BUS=usb
ID_MODEL=iPad
ID_MODEL_ENC=iPad
ID_MODEL_ID=12ab
ID_SERIAL=Apple_Inc._iPad_3e4245d06e90def26aa720dfb8d05d6634aa3d00
ID_SERIAL_SHORT=3e4245d06e90def26aa720dfb8d05d6634aa3d00
ID_VENDOR=Apple_Inc.
ID_VENDOR_ENC=Apple\x20Inc.
ID_VENDOR_ID=05ac
ID_REVISION=0704
ID_USB_MODEL=iPad
ID_USB_MODEL_ENC=iPad
ID_USB_MODEL_ID=12ab
ID_USB_SERIAL=Apple_Inc._iPad_3e4245d06e90def26aa720dfb8d05d6634aa3d00
ID_USB_SERIAL_SHORT=3e4245d06e90def26aa720dfb8d05d6634aa3d00
ID_USB_VENDOR=Apple_Inc.
ID_USB_VENDOR_ENC=Apple\x20Inc.
ID_USB_VENDOR_ID=05ac
ID_USB_REVISION=0704
ID_USB_INTERFACES=:060101:010100:010200:030000:fffe02:fffd01:
ID_VENDOR_FROM_DATABASE=Apple, Inc.
ID_MODEL_FROM_DATABASE=iPad
ID_PATH_WITH_USB_REVISION=pci-0000:00:14.0-usbv2-0:2
ID_PATH=pci-0000:00:14.0-usb-0:2
ID_PATH_TAG=pci-0000_00_14_0-usb-0_2
ID_FOR_SEAT=usb-pci-0000_00_14_0-usb-0_2
MAJOR=189
MINOR=46
TAGS=:systemd:uaccess:seat:
CURRENT_TAGS=:systemd:uaccess:seat:

UDEV  [24386.217983] remove   /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0 (usb)
ACTION=remove
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=6/1/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00ic06isc01ip01in00
SEQNUM=26253
USEC_INITIALIZED=24385405469
ID_VENDOR_FROM_DATABASE=Apple, Inc.
ID_MODEL_FROM_DATABASE=iPad
ID_PATH_WITH_USB_REVISION=pci-0000:00:14.0-usbv2-0:2:1.0
ID_PATH=pci-0000:00:14.0-usb-0:2:1.0
ID_PATH_TAG=pci-0000_00_14_0-usb-0_2_1_0

UDEV  [24386.218470] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.0 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=6/1/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00ic06isc01ip01in00
SEQNUM=26256
USEC_INITIALIZED=24386215468
ID_VENDOR_FROM_DATABASE=Apple, Inc.
ID_MODEL_FROM_DATABASE=iPad
ID_PATH_WITH_USB_REVISION=pci-0000:00:14.0-usbv2-0:2:4.0
ID_PATH=pci-0000:00:14.0-usb-0:2:4.0
ID_PATH_TAG=pci-0000_00_14_0-usb-0_2_4_0

UDEV  [24386.218580] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.1 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.1
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=255/254/2
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00icFFiscFEip02in01
SEQNUM=26257
USEC_INITIALIZED=24386215753
ID_VENDOR_FROM_DATABASE=Apple, Inc.
ID_MODEL_FROM_DATABASE=iPad
ID_PATH_WITH_USB_REVISION=pci-0000:00:14.0-usbv2-0:2:4.1
ID_PATH=pci-0000:00:14.0-usb-0:2:4.1
ID_PATH_TAG=pci-0000_00_14_0-usb-0_2_4_1
DRIVER=usbfs

UDEV  [24386.218693] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=6/1/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00ic06isc01ip01in00
SEQNUM=26254
USEC_INITIALIZED=24385409089
ID_VENDOR_FROM_DATABASE=Apple, Inc.
ID_MODEL_FROM_DATABASE=iPad
ID_PATH_WITH_USB_REVISION=pci-0000:00:14.0-usbv2-0:2:1.0
ID_PATH=pci-0000:00:14.0-usb-0:2:1.0
ID_PATH_TAG=pci-0000_00_14_0-usb-0_2_1_0

UDEV  [24386.218856] add      /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.2 (usb)
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:4.2
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=255/253/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00icFFiscFDip01in02
SEQNUM=26258
USEC_INITIALIZED=24386215785
ID_VENDOR_FROM_DATABASE=Apple, Inc.
ID_MODEL_FROM_DATABASE=iPad
ID_PATH_WITH_USB_REVISION=pci-0000:00:14.0-usbv2-0:2:4.2
ID_PATH=pci-0000:00:14.0-usb-0:2:4.2
ID_PATH_TAG=pci-0000_00_14_0-usb-0_2_4_2

UDEV  [24386.218964] remove   /devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0 (usb)
ACTION=remove
DEVPATH=/devices/pci0000:00/0000:00:14.0/usb1/1-2/1-2:1.0
SUBSYSTEM=usb
DEVTYPE=usb_interface
PRODUCT=5ac/12ab/704
TYPE=0/0/0
INTERFACE=6/1/1
MODALIAS=usb:v05ACp12ABd0704dc00dsc00dp00ic06isc01ip01in00
SEQNUM=26255
USEC_INITIALIZED=24385409089
ID_VENDOR_FROM_DATABASE=Apple, Inc.
ID_MODEL_FROM_DATABASE=iPad
ID_PATH_WITH_USB_REVISION=pci-0000:00:14.0-usbv2-0:2:1.0
ID_PATH=pci-0000:00:14.0-usb-0:2:1.0
ID_PATH_TAG=pci-0000_00_14_0-usb-0_2_1_0