how to know a usb device is plugged in/out

lordofring · 04-25-2005, 12:40 PM

Hello,

My application needs to be notified when a usb device is plugged in/out. I know the file /proc/bus/usb/devices is changed whenever a usb device is plugged in/out. But how do I know the file is changed. May I use poll(() function to wait for the file changing? (I don't want to read the file every second to see the chaning.)

Thanks in advance.

acid_kewpie · 04-25-2005, 12:49 PM

not sure if you're going from a programming angle with the references to poll() there, but i'd suggest you look toward udev rules, assuming you're using udev of course. in a specific rule you can set a PROGRAM= variable to run a script on a device being connected. not sure about disconnection, as i've never done it, but i expect it's simple.

lordofring · 04-25-2005, 01:15 PM

Your guess is correct. My question is about programming. My application needs to monitor usb devices plugged in/out. And I don't think I can use udev since my kernel is 2.4.28. Thanks anyway.