Finding vendor id and product id of a usb device

Every usb device that we plug into a system has a vendo id and a product id that uniquely identifies the device. The vendor id is given by the usb.org to the vendor who in turn assigns unique product id to the products they manufacture. The kernel uses these product id and vendor id to find out if the driver supports the device or not.
To find the vendor id and product id of a device we can use the command "usb-devices" . The command lists out details of all the usb busses in the system and if any device is connected to any of the bus, it gives information of that device.

For eg:

$ usb-devices 

T:  Bus=01 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=480 MxCh= 6
D:  Ver= 2.00 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=1d6b ProdID=0002 Rev=02.06
S:  Manufacturer=Linux 2.6.32-5-686 ehci_hcd
S:  Product=EHCI Host Controller
S:  SerialNumber=0000:00:02.2
C:  #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub


T:  Bus=01 Lev=01 Prnt=01 Port=02 Cnt=01 Dev#=  2 Spd=480 MxCh= 0
D:  Ver= 2.00 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=0bc2 ProdID=5021 Rev=01.48
S:  Manufacturer=Seagate
S:  Product=FreeAgent GoFlex
S:  SerialNumber=NA01ZA6B
C:  #Ifs= 1 Cfg#= 1 Atr=80 MxPwr=100mA
I:  If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50 Driver=usb-storage


T:  Bus=02 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 3
D:  Ver= 1.10 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=1d6b ProdID=0001 Rev=02.06
S:  Manufacturer=Linux 2.6.32-5-686 ohci_hcd
S:  Product=OHCI Host Controller
S:  SerialNumber=0000:00:02.0
C:  #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub


T:  Bus=03 Lev=00 Prnt=00 Port=00 Cnt=00 Dev#=  1 Spd=12  MxCh= 3
D:  Ver= 1.10 Cls=09(hub  ) Sub=00 Prot=00 MxPS=64 #Cfgs=  1
P:  Vendor=1d6b ProdID=0001 Rev=02.06
S:  Manufacturer=Linux 2.6.32-5-686 ohci_hcd
S:  Product=OHCI Host Controller
S:  SerialNumber=0000:00:02.1
C:  #Ifs= 1 Cfg#= 1 Atr=e0 MxPwr=0mA
I:  If#= 0 Alt= 0 #EPs= 1 Cls=09(hub  ) Sub=00 Prot=00 Driver=hub

The above output gives the information for Bus01,Bus02,Bus03.

If we observe the second set of output for Bus01 we can see that it gives us  details of a USB device whose manufacturer is Seagate. The product name is FreeAgent Goflex and the Vendor id is 0bc2 the product id is 5021. (The specific output is made into bold only for reference).

The other buses  do not have any device connected hence it only gives information of the bus, and the manufacturer by default is set to linux.