[sclug] Can't able to create user with DOTS?

Jonathan H N Chin jc254 at newton.cam.ac.uk
Tue Mar 1 18:34:13 UTC 2005

James Beckett <sclug at hackery.net> wrote:
> On Tue, 2005-03-01 at 15:38, Navneet wrote:
> >    I can't able to create users having decimal point(s) in their name.
> > i.e navneet.kc
> > Notice: decimal point between navneet & kc.
> That's right, you can't.

If he can't, it's not because it's not possible to do.
I just checked by creating "jhnc.wibble" by hand on debian,
Solaris, HP-UX and IRIX: Works fine on all of them.

It's more likely that the tool being used to add the account
has a "sanity check" that is disallowing it.

For example: debian's adduser returns:

  # adduser jhnc.wibble
  adduser: Please enter a username matching the regular expression configured
  via the name_regex configuration variable.  Use the `--force-badname'
  option to relax this check or reconfigure name_regex.

while Solaris's useradd says:

  # useradd jhnc.wibble
  UX: useradd: jhnc.wibble name too long.

Note that even if you create the account, some software may break.
Typical systems expect usernames to be at most 8 characters long.
Breakage may be mostly benign (eg. truncated display in "ls"),
but I wouldn't count on it.

Another note: Mixed-case usernames are also perfectly valid.
However, some software expects usernames to be all lowercase
and may behave in unexpected ways if they areen't.

For example, sendmail converts localpart to lowercase before
expanding aliases. (I actually make use of this to create accounts
that mustn't receive email).


Jonathan H N Chin, 2 dan | deputy computer | Newton Institute, Cambridge, UK
<jc254 at newton.cam.ac.uk> | systems mangler | tel/fax: +44 1223 767091/330508

                "respondeo etsi mutabor" --Rosenstock-Huessy

More information about the Sclug mailing list