NAME
biff -- be notified if mail arrives and who it is from
[…]
HISTORY
The biff command appeared in 4.0BSD. It was named after the dog of
Heidi Stettner. He died in August 1993, at 15.
Eric Cooper, a student contemporary to Foderero and
Stettner, reports that the dog would bark at the mail
carrier,[4][5] making it a natural choice for the name
of a mail notification system. Stettner herself
contradicts this.[3][6]
Sending mail to root@<whatever> really did use to be a pretty reliable way of getting somebody useful's attention - the early-to-mid 90s equivalent of making a "Can someone from Google please unlock my account?" post on HN.
Under Debian/Ubuntu, when Postfix is installed, part of the standard list of questions that dpkg-reconfigure asks you is how you want mail flow to work: you can give it a central smarthost. So any local mail gets sent on, and on the central mail hub you can tell it to send root@ to someplace useful:
This is a fair critique actually. And this shouldn't be the default. It is for now because I haven't gotten around to making Biff read your POSIX locale settings and converting them to a Unicode locale. If you build with `cargo build --release --features locale` (or get Biff from a release binary), then you can do:
$ BIFF_LOCALE=en-US biff
Thu, May 28, 2026, 6:38:09 AM EDT
If that doesn't work, then you can enable logging to see an error message:
$ BIFF_LOCALE=watwat BIFF_LOG=warn biff
2026-05-28T06:39:08.876336708-04:00[America/New_York]|WARN|src/main.rs:76: reading `BIFF_LOCALE` failed, using unknown locale `und`: failed to parse `BIFF_LOCALE` environment variable: The given language subtag is invalid
2026 M05 28, Thu 06:39:08
What you're seeing is what ICU4X does when the user's locale is unknown or undetermined. The `M` prefix occurs to indicate that the number is the month, and is unrelated to the name. For example:
$ BIFF_LOCALE=watwat biff time fmt -f '%c' '1 month'
2026 M06 28, Sun 06:39:50
No, Biff informs the system whether you want to be notified when mail arrives during the current terminal session.
Yeah the name collision is unfortunate, but probably fine. The name Biff was just too good to pass up.
The name comes from the fact that Biff is a character in Back to the Future, and it rhymes with Jiff[1]. Jiff is the datetime library that Biff uses.
"Make like a tree and get out of here!" https://www.youtube.com/shorts/9Jabplo2pZU
[1]: https://github.com/BurntSushi/jiff
I.e.,
* https://man.freebsd.org/cgi/man.cgi?query=biff * https://en.wikipedia.org/wiki/Biff_(Unix)Also: <https://manpages.debian.org/stable/biff/biff.1.en.html>
exactly. and chromium is a good looking space shooter with too few levels!
Yes I'm sure root is anxious to read all the mail in their local mailbox
Sending mail to root@<whatever> really did use to be a pretty reliable way of getting somebody useful's attention - the early-to-mid 90s equivalent of making a "Can someone from Google please unlock my account?" post on HN.
Under Debian/Ubuntu, when Postfix is installed, part of the standard list of questions that dpkg-reconfigure asks you is how you want mail flow to work: you can give it a central smarthost. So any local mail gets sent on, and on the central mail hub you can tell it to send root@ to someplace useful:
* https://wiki.debian.org/Postfix#Forward_Emails
I remember when biff was what we ran in a CSH to be informed of new email. I don’t remember if this was a local UCB tool or if it was part of BSD.
Same dude that made jiff. Love that library, so I'm assuming biff is built on top of jiff.
also made ripgrep
I am a happy user of dateutils [0], but I will try out Biff and see which one is more ergonomic.
[0]: https://www.fresse.org/dateutils/
% biff
2026 M05 28, Thu 17:27:46
Ahh, the month of M05
This is a fair critique actually. And this shouldn't be the default. It is for now because I haven't gotten around to making Biff read your POSIX locale settings and converting them to a Unicode locale. If you build with `cargo build --release --features locale` (or get Biff from a release binary), then you can do:
If that doesn't work, then you can enable logging to see an error message: What you're seeing is what ICU4X does when the user's locale is unknown or undetermined. The `M` prefix occurs to indicate that the number is the month, and is unrelated to the name. For example:just between a04 and j06 yes
Looking forward to the J07 04 holiday