Real-world non-alphanumeric usernames

Posted Dec 5, 2024 19:40 UTC (Thu) by dskoll (subscriber, #1630)
In reply to: Real-world non-alphanumeric usernames by rweikusat2
Parent article: Debian opens a can of username worms

The local-part of your email address doesn't have to be your UNIX user name, though. It often is for convenience, but while the local-part of my email address is dianne, that is not my UNIX login name.

So appealing to email as a reason to restrict UNIX login names is not a great argument. I think a better argument is simply to make life easier for programs that need to deal with login names and that don't want to worry about UTF-8 canonicalization, etc.

Real-world non-alphanumeric usernames

Posted Dec 5, 2024 19:51 UTC (Thu) by rweikusat2 (subscriber, #117920) [Link] (9 responses)

Regardless of what someone's public email address might be, username@hostname, hostname here both referring to the actual hostname and the host FQDN, is always also a valid email address. The implication of this is mostly that "programs dealing with login names" include any MTA ever written for UNIX and very likely, all other programs ever written to handle email on UNIX, IOW, to name the (probably) most scary example, if you want to allow UTF8 in usernames, are prepared to patch sendmail and procmail to support that?

Real-world non-alphanumeric usernames

Posted Dec 5, 2024 20:57 UTC (Thu) by zeha (subscriber, #61580) [Link] (2 responses)

It was already discovered that various MTAs and MUAs cannot deal with non-ascii in gecos, so clearly these programs no longer matter.

Real-world non-alphanumeric usernames

Posted Dec 5, 2024 21:09 UTC (Thu) by rweikusat2 (subscriber, #117920) [Link]

These were some technical remarks about usernames and not an invitation to an open-ended policy discussion about who dictates (or believe he should really get to dictate) what has to "matter" to other people.

Real-world non-alphanumeric usernames

Posted Dec 6, 2024 19:43 UTC (Fri) by raven667 (subscriber, #5198) [Link]

> It was already discovered that various MTAs and MUAs cannot deal with non-ascii in gecos, so clearly these programs no longer matter.

I think it's worth the effort to identify and fix those programs so people can use their real name for display in the way they prefer to see it regardless of what language they use. If there is no one maintaining a particular MTA or MUA or whatever that breaks because of this, then you've learned that unmaintained software eventually breaks when the world changes around it, but this kind of change could be eased into over several release cycles by making it optional while bug reports and testing are done, before accepting it as the default and a blocker.

Real-world non-alphanumeric usernames

Posted Dec 5, 2024 21:23 UTC (Thu) by dskoll (subscriber, #1630) [Link] (5 responses)

No, that would not be fun, but still... appealing to email addresses as a reason to restrict usernames isn't a good argument. Some email systems store email in ways that don't necessarily depend on UNIX login names at all (for example, Cyrus IMAP.)

Real-world non-alphanumeric usernames

Posted Dec 5, 2024 21:59 UTC (Thu) by rweikusat2 (subscriber, #117920) [Link] (4 responses)

Email systems which weren't based on UNIX have existed since before UNIX gained any networking capabilities (AFAICT, even before UUCP) but that's besides the point. A UNIX system is also an email system and this system is based on using the UNIX username as local-part of an internet email address. That's just a technical fact people considering to extend the username syntax to include octets outside of the range of printable ASCII characters might want to take into account. Or not, depending on what their priorities are.

Real-world non-alphanumeric usernames

Posted Dec 5, 2024 23:26 UTC (Thu) by Wol (subscriber, #4433) [Link]

> Email systems which weren't based on UNIX have existed since before UNIX gained any networking capabilities

I think the birth of email actually predates the birth of Unix?

Cheers,
Wol

UNIX and email

Posted Dec 5, 2024 23:47 UTC (Thu) by KJ7RRV (subscriber, #153595) [Link]

> A UNIX system is also an email system and this system is based on using the UNIX username as local-part of an internet email address.

I think I'm misunderstanding this part? It seems to mean that all UNIX systems are email servers; is that correct?

Real-world non-alphanumeric usernames

Posted Dec 6, 2024 0:15 UTC (Fri) by dvdeug (guest, #10998) [Link] (1 responses)

> A UNIX system is also an email system

A fully POSIX-compliant UNIX system has an email system, though in the modern world, very few UNIX systems are connected to Internet email. I wouldn't say it's not UNIX if it doesn't have an email system. I removed mailutils, mailx, and mailcap from my Debian unstable system, and nothing depended on them. The concept of open access to email via Internet has been lost, and system-wide email isn't very useful on a single-user system.

Real-world non-alphanumeric usernames

Posted Dec 6, 2024 4:42 UTC (Fri) by KJ7RRV (subscriber, #153595) [Link]

Thank you! I didn't realize that POSIX requires email; that explains it.