[Rets-dev] Email validation regular expression

[Paul Stusiak]

I think that the one that is in place already is sufficiently ugly :-)

Also, several of the validation libraries cannot handle characters 
escaped in the fashion below or understand \w or \d. You need to use the 
entity values. You've got to love half baked solutions where only a 
portion of the reg ex can be expressed - sigh. It would be really nice 
if there was a standard regular expression language that was used by 
everyone, but there isn't (never mind the i18n quagmire).

Paul

Matt Lavallee wrote:
> Alright, here we go:
> ^(?:[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+\.)*[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`
> \{\|\}(\\\@)\~]+@(?:(?:(?:[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!\.)){0,61}[a-zA-Z0-9]?\.
> )+[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!$)){0,61}[a-zA-Z0-9]?)|(?:\[(?:(?:[01]?\d{1,2}|2
> [0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\]))$
>
> I think that's ugly enough. ;)
>
> -Matt
>
>   
>> -----Original Message-----
>> From: Paul Stusiak [mailto:pstusiak at falcontechnologies.com]
>> Sent: Wednesday, April 25, 2007 4:07 PM
>> To: Matt Lavallee
>> Cc: rets-dev at rets.org
>> Subject: Re: [Rets-dev] Email validation regular expression
>>
>> Thank you for the suggestion.
>>
>> Your suggestion does not validate the following valid email addresses:
>>
>> !def!xyz%abc at local.example.com
>> a.one_two{}@some.example.com
>> a.one_two at some.example.com
>> some\@one at example.com
>>
>> which was tested using the on-line regex testing tool
>> http://www.fileformat.info/tool/regex.htm
>>
>> A good location for regular expressions is here
>> http://regexlib.com/
>>
>> search for email. There is grading (use with caution, the results don't
>> always match the grade...)
>>
>> This is where the root of the regex came from that is in the Phone.xsd.
>> I've also seen regular expressions that enumerate the possible top level
>> domains - this strikes me as a bad thing for a standard since the
>> addition of new top level domains which happens on a regular basis,
>> would require a change to the schema.
>>
>> Also note that xsd do not use the '^' and '$' to indicate the start and
>> end of line.
>>
>> As noted in the schema, the patterned used does not cover all cases, but
>> does cover the first three above but not the some\@one at example.com
>> pattern where reserved characters are escaped. It didn't seem necessary
>> to me.
>>
>>     
[snip]

-- 
Paul Stusiak
Falcon Technologies Corp.