Why are dots in username & groupname no longer allowed?

[wmcdonald at gmail.com (Will McDonald)]

On 06/01/06, Johnny Hughes <mailing-lists@xxxxxxxxxxxx> wrote:
> I disagree ... not that it matters what I think.  If chown and chgrp
> allow dots to seperate user and group, I don't think they should not be
> allowed in user names (or at least this should be a major factor to
> consider).

"I don't think they should not be allowed", is that double negative
intentional? :)

I think '.' as a separator for chown etc. is a GNU thing. I seem to
remember Solaris only accepts ':'.

http://www.cs.biu.ac.il/cgi-bin/man?chown+1

FWIW, using '.' as a separator isn't documented in the GNU chown man page.

Will.