| Date: Thu, 19 Oct 2006 12:33:31 +0100
| From: jm at jmason.org (Justin Mason)
| Pádraig Brady writes:
| > Does anyone know of existing systems that use numeric usernames?
| > There is a proposal to change `chown 1234 file` in coreutils
| > to not look for a user name 1234 first, and just assume one means
| > the user id 1234. [ ... ]
| I can't think of one -- but the principle of least surprise would
| dictate at least *checking* getpwnam() first.
back when I was working on sys admin and security tools
for a Unix company a long long time ago in a place far
far away, this issue came up. the same idea (back then)
was driven by getpwnam(3) being slow.
I don't recall the arguments used against the idea then,
and the only rationale I can recall being used for the
idea was that getpwnam(3) was slow (esp., AFAICR, if the
NIS/YP/whatever server was inaccessible). hence, if my
memory is correct, the alternative which I _think_ was
ultimately implemented (cannot recall for certain now):
an option (`-n' or something, cannot recall now): if
`-n' was given, then the "name" had to be numeric (an
error otherwise), and was taken as the numeric UID.
also --- what I can recall more slightly clearly (since
I did or reviewed some of this work meself) --- is the
account creation tools (equivalent of useradd(8) &tc)
refused to create a numeric account. the tool which
checked the various files for consistency (`pwcheck' or
something, not sure if there is a Linux/GNU equivalent?)
whinged if it found a numeric username (or groupname).
however, the tools that modified an existing account
(e.g., passwd(1) &tc) were quite happy to work with
numeric usernames. hence, you had to "roll yer own"
to create such beasties, but if you had created them,
you were told this is a bad idea yet all the nominal
stuff still worked.
my memory is rather flakey here, and I'm not claiming
the above is 100% accurate, but that's how I recall the
same idea(/issue?) a universe away being dealt with.
this was all pre-POSIX, using K&R-1 C, which gives you
an idea just how long ago this was .... ;-\
Experienced (20+ yrs) kernel/software Eng: | Brian Foster Montpellier,
• Unix, embedded, &tc; • Linux; • doc; | blf at utvinternet.ie FRANCE
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