PCRE regexp bug ?

[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...

[Greg Wiley]

----- Original Message -----
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...

>

Maybe it thinks it's the letter O, have you tried using a font that puts a
line through the zero;-)

[sorry couldn't resist]

Cheers, Greg.

[Marek Kilimajer]

Not an answer but
'/^[[:alpha:]]{1,1}$/'
could be writen as
'/^[[:alpha:]]$/'


[email]tpc@csua.berkeley.edu[/email] wrote:

> 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...
>
>

[Cpt John W. Holmes]

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...