I wrote once many years ago, showing me all my TOTP codes in a terminal. I'd run it on a text-only offline/airgapped Raspberry Pi (an old one, with not even WiF

I wrote once many years ago, showing me all my TOTP codes in a terminal. I'd run it on a text-only offline/airgapped Raspberry Pi (an old one, with not even WiFi capabilities). I was also pissed off by the clock issue, so I'd show both the previous, present and next code to come: because it's really a PITA when you see 213987 but you've got only two seconds left before it rolls. So I may as well start entering the next code (what the server accept is something not in my control). And I always, always, always have a known, public, 2FA which I can use to double-check that everything is smooth (for example by entering it on some online computer and verifying that I get the same tokens generated). I just reused whatever 2FA/TOTP Java library I found and wrapped that in a little CLI utility. My secrets were unlocked by entering a password when I'd start the app.