/usr/sbin/lsusb
Bus 004 Device 004: ID 066f:821c SigmaTel, Inc.
Bus 004 Device 003: ID 04a9:10b7 Canon, Inc.
Bus 004 Device 001: ID 0000:0000
Bus 003 Device 001: ID 0000:0000
Bus 002 Device 001: ID 0000:0000
Bus 001 Device 004: ID 046d:c018 Logitech, Inc.
Bus 001 Device 001: ID 0000:0000