How are USB ports assigned?

pixellany · 12-12-2005, 04:43 PM

I have seen hints of this, but never the "whole story". What is the definitive way of knowing what device corresponds to an entry in /dev?
I'm asking about all devices, but the question comes up most often for usb.

dmartins · 12-13-2005, 10:17 AM

If you are using udev, and AFAIK most modern distros are, the udevinfo tool is quite useful for finding all kinds of information about a device node.

Code:

udevinfo -a -p $(udevinfo -q path -n /dev/device)

Check out http://www.reactivated.net/writing_udev_rules.html for a bit more info on how this works.

Edit: i guess that's not really a definitive way.. just a hit that'll work pretty much all of the time