From: dblack@...
Date: 2006-01-04T21:15:01+09:00
Subject: Re: Email Address Regex [was Re: silly regex question]

Hi --

On Wed, 4 Jan 2006, Jacob Fugal wrote:

> On 1/3/06, Dan Kohn <dan@dankohn.com> wrote:
>> Here's a rails example for validating email addresses.
>>
>>   validates_format_of :login, :with => /
>>     ^[-^!$#%&'*+\/=?`{|}~.\w]+
>>     @[a-zA-Z0-9]([-a-zA-Z0-9]*[a-zA-Z0-9])*
>>     (\.[a-zA-Z0-9]([-a-zA-Z0-9]*[a-zA-Z0-9])*)+$/x,
>>     :message => "must be a valid email address",
>>     :on => :create
>
> Be careful with email validation via regex, it's harder than you might
> think[1][2]:
>
> /^([a-zA-Z0-9&_?\/`!|#*$^%=~{}+'-]+|"([\x00-\x0C\x0E-\x21\x23-\x5B\x5D
> -\x7F]|\\[\x00-\x7F])*")(\.([a-zA-Z0-9&_?\/`!|#*$^%=~{}+'-]+|"([\x00-\
> x0C\x0E-\x21\x23-\x5B\x5D-\x7F]|\\[\x00-\x7F])*"))*@([a-zA-Z0-9&_?\/`!
> |#*$^%=~{}+'-]+|\[([\x00-\x0C\x0E-\x5A\x5E-\x7F]|\\[\x00-\x7F])*\])(\.
> ([a-zA-Z0-9&_?\/`!|#*$^%=~{}+'-]+|\[([\x00-\x0C\x0E-\x5A\x5E-\x7F]|\\[
> \x00-\x7F])*\]))*$/

See also: http://www.ex-parrot.com/~pdw/Mail-RFC822-Address.html


David

-- 
David A. Black
dblack@wobblini.net

"Ruby for Rails", from Manning Publications, coming April 2006!
http://www.manning.com/books/black