I think you will find the file is not truly empty. /sys is not an actual file system, merely an interface to kernel information. There is no directory structure that records the length or other attributes of a file, as is the case for data on real media such as disks. If you read the /sys/kernel/debug/usb/devices file, you should find the data you seek. _______________________________________________ test mailing list -- test@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to test-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://getfedora.org/code-of-conduct.html List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/test@xxxxxxxxxxxxxxxxxxxxxxx