Re: [PHP] PCRE regexp bug ?

I believe I spoke too soon. If I use isset() then even if I leave the
field empty it still returns true. I am trying to view the documentation for
this function but php.net seems to be timing out now.

On Fri, 15 Aug 2003 tpc@csua.berkeley.edu wrote:

>
> Thank you. I did the following:
>
> if (isset($_POST[MI]) && (preg_match('/^[[:alpha:]]{1,1}$/', $_POST[MI]) == 0))
>
> and zero is caught.
>
> On Fri, 15 Aug 2003, CPT John W. Holmes wrote:
>
> > From: <tpc@csua.berkeley.edu>
> >
> > > I use preg_match to validate the Middle Initial field of a form and so far
> > > it works, except yesterday a user submitted a "0" (zero) as a middle
> > > initial! My regexp is:
> > >
> > > if (!empty($_POST[MI]) && (preg_match('/^[[:alpha:]]{1,1}$/', $_POST[MI])
> > == 0))
> > >
> > > I tested it with 0-9 and my regexp catches every digit except 0.
> > Curious...
> >
> > empty("0") is going to be true. So, !empty("0") is going to be false, so you
> > won't "catch" the zero.
> >
> > ---John Holmes...
> >
> >
>
>

* Thus wrote tpc@csua.berkeley.edu (tpc@csua.berkeley.edu):
>
> I believe I spoke too soon. If I use isset() then even if I leave the
> field empty it still returns true. I am trying to view the documentation for
> this function but php.net seems to be timing out now.

> > if (isset($_POST[MI]) && (preg_match('/^[[:alpha:]]{1,1}$/', $_POST[MI]) == 0))


That is because the browser is sending in the POST data:
MI=

Thus, php does set it to ''.

Use something like this instead:

if (strlen($_POST['MI'])) ...


btw, you should really quote your array keys.

HTH,


Curt
--
"I used to think I was indecisive, but now I'm not so sure."