Subject: Re: useradd: spaces and $ in usernames
To: None <firstname.lastname@example.org>
From: der Mouse <mouse@Rodents.Montreal.QC.CA>
Date: 11/15/2001 21:27:35
> Usernames  have had a specific character limitation for a Very Long
Where is this restriction documented, and what exactly _is_ the
restriction? I've been hanging around UNIX variants for long enough
that I'd've expected to have picked up on it, but I don't recall
anything of the sort. I've seen "alphanumeric, ., _, -"; does that
include non-ASCII letters, and if so, in which charset? (And if not,
do _you_ want to be the one who tells Søren "I'm sorry, Hels can have
username hels, but you can't have username søren, because our OS is
stuck in an English-centric view of the world? :-)
And, speaking of that limitation...where did it go? As I reported, I
tried a control-B in a username and it passed smoke-test, at least. Is
there something critical I didn't try that would fall over?
> Opening up spaces and $s is, IMHO, asking for trouble.
Perhaps. But the system is already full enough of foot-pointed pistols
that I don't see much harm in one more. Especially when, as the
message that started this off noted, there's something useful that
requires this particular one.
> At the very _least_, if you add this `feature', add a compatibility
> note to the manpage that indicates that much third party software
> assumes alphanumeric/./_/- usernames.
That sounds entirely reasonable. You might also note that having
multiple usernames that differ only in alphabetic case is likely to
cause trouble, too.
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