On Feb 12, 3:49 am, "J. mp" <joaomiguel.pere... / gmail.com> wrote:
> Gavin Kistner wrote:
> > /\A[a-z][a-z.-]{3,28}[a-z]\Z/i
[snip]
> > Note that, per your exact instructions, this allows:
> >   u_s_e_r_n_a_m_e
> >   u____________________________e
> >   z._-_.z
>
> Oh damm!! the first should  be allowed but second and the third should
> not be allowed

OK, but *why* aren't they allowed. You haven't described exactly what
your requirements are. Is it because you can't have to non-letters in
a row? Is it because the string must contain at least three letters?

BTW, where are these requirements coming from? Are these business
requirements that must be enforced? Are you just making up what you
think people should probably have to use as a name? Or are you just
trying to learn regexp?