Linux How can I prove if udev installed?

Question

How can I prove if udev is installed and working proper? Just call udevadm would be a method, right?

Solution 1

Make sure the udev daemon udevd is running:

if [[ $(pgrep -c udevd) -eq 0 ]]; then
    echo "No udev"
else
    echo "udev is running"
fi

Or check the output of service udev status which contains start/running if udev is running.

Solution 2

If you what to test your udev is running and working. do following to verify.

Delete one of devices from /dev

rm /dev/fd0

Run udevtrigger, it will auto create missing device again.

/sbin/udevtrigger

Solution 3

@Peter - If device is gone you can create them back using following command.

[root@mg0016 ~]# mknod /tmp/fd0 b 2 0
[root@mg0016 ~]# ls -l /tmp/fd0
brw-r--r-- 1 root root 2, 0 Sep  7 10:09 /tmp/fd0

Comments

[Admin]

@ Satish Thanks for the answer, just one problem with your solution. If I delete the device and udev is not running, the device is gone :)