Run something when USB device is plugged in doesn't work

4
votes

I made a script in /etc/udev/rules.d/local.rules

SUBSYSTEM=="usb", SYSFS{idVendor=="b58e"}, SYSFS{idProduct=="9e84"}, ACTION=="add", RUN+="notify-send USB"

I then reload udev with

 sudo udevadm control --reload-rules

I've tried to remove everything but subsystem and run. I've tried the run '=' instead of '+=', I've tired ATTR instead of SYSFS. I tried "sudo service udev restart" and "sudo reload udev". I unplug the device, then plug it in again and it does not run the action. I tried renaming it 70-local.rules and changing permissions to a+x. I've tried changing 'subsystem' to 'bus'. I've tried setting run to be "/path/test.sh" which has the same command.

2
linuxubuntuusbudevkubuntu

2 Answers

11
votes

I'm not an expert and this isn't an answer, but I've found the following steps useful in identifying the appropriate attributes to trigger on:

  1. Locate the device path using udevadm, lsusb, or usb-devices. I normally just use lsusb and let tab completion in my shell guide me. In my case, the path is /dev/bus/usb/003/007.
  2. Use udevadm to identify the device attributes for rule writing. In my case, I used udevadm info -a --attribute-walk --root --name=/dev/bus/usb/003/007.
  3. Write the rule and check that it's triggering. In my case, I'm just changing the device owner to user "stephen" and it's very easy for me to check if it's working by using ls -l /dev/bus/usb/003/007. My rule for this case looks like: SUBSYSTEM=="usb", ATTR{idVendor}=="18d1", OWNER="stephen". I have a similar rule that puzzled me for a little while because the subsystem was expecting ATTRS not ATTR, which is why I recommend walking the attributes. The rule in this latter case became: `SUBSYSTEM=="tty", ATTRS{idVendor}=="0403", ATTRS{idProduct}=="6001", OWNER="stephen".

And, of course, man udev is always helpful. As you said, you should struggle to identify that your rule is triggering properly and may be best off just doing a quick ownership change on the device as I did for a first step. You can run into trouble with bad attributes or symbolic links sometimes and it's

3
votes

it does not run the action

No, it runs the action. The problem is that it doesn't know where to send the notification, since there's no notification framework running when udev starts. You will need to send a DBus message across the system bus and have a user daemon catch the message and post a notification instead.