Bit Warden password manager app for Linux desktop has an option to clear the clipboard:

file -> settings [options]'clear clipboard': dropdown select range from 10 seconds to 5 mins or never.

Set & forget.

KeePassXC does this as well. Even if just copying the username.

I recently came across a site called Leanpub [https://leanpub.com/] while searching for Jeff Geerling's ebook on 'Ansible for Devops'.

The company looks to be ethical, and is aimed at Technical authors who wish to self publish ebooks. Each ebook sold displays how much the author will receive from the purchase (usually 80%).

Most Leanpub books are available in PDF, EPUB, and MOBI.

If you buy a Leanpub book, you get free updates for as long as the author updates the book [which Jeff Geerling seems to regularly do]

The big plus is that Leanpub books don't have any DRM copy-protection.