regex an email

[otuatail]

Hi I have been given a link to a website here for validating an email. It is very extensive and comes with a list of valid and invalid email address to test. The problem is, one of the emails that fails passes.

 

gatsby@f.sc.

 

this should fail as it ends with a (.)

 

Can anyone find the offending part of the regex.

 

function validEmail($email) // RFC 2822 3.4.1    a-z0-9!#$%&'*+-/=?^_`{|}~
{
   $isValid = 1;
   $atIndex = strrpos($email, "@");
   if (is_bool($atIndex) && !$atIndex)
   {
      $isValid = 0;
   }
   else
   {
      $domain = substr($email, $atIndex+1);
      $local = substr($email, 0, $atIndex);
      $localLen = strlen($local);
      $domainLen = strlen($domain);
      if ($localLen < 1 || $localLen > 64)
      {
         // local part length exceeded
         $isValid = 0;
      }
      else if ($domainLen < 1 || $domainLen > 255)
      {
         // domain part length exceeded
         $isValid = 0;
      }
      else if ($local[0] == '.' || $local[$localLen-1] == '.')
      {
         // local part starts or ends with '.'
         $isValid = 0;
      }
      else if (preg_match('/\\.\\./', $local))
      {
         // local part has two consecutive dots
         $isValid = 0;
      }
      else if (!preg_match('/^[A-Za-z0-9\\-\\.]+$/', $domain))
      {
         // character not valid in domain part
         $isValid = 0;
      }
      else if (preg_match('/\\.\\./', $domain))
      {
         // domain part has two consecutive dots
         $isValid = 0;
      }
      else if
(!preg_match('/^(\\\\.|[A-Za-z0-9!#%&`_=\\/$\'*+?^{}|~.-])+$/',
                 str_replace("\\\\","",$local)))
      {
         // character not valid in local part unless 
         // local part is quoted
         if (!preg_match('/^"(\\\\"|[^"])+"$/',
             str_replace("\\\\","",$local)))
         {
            $isValid = 0;
         }
      }
		/*
      if ($isValid && !(checkdnsrr($domain,"MX") || ?checkdnsrr($domain,"A")))
      {
         // domain not found in DNS
         $isValid = 0;
      }*/
   }
   return $isValid;
}

// Some Useful VB functions
function Cint($value)
{
    if(!is_numeric($value))
      return 0;
    else
      return (int)$value;
}

 

Sorry about this but I cant get my head around this level of regex.

 

Desmond.

 

[Psycho]

Not interested in wading through all of that code, especially when I have a two line function that will validate an email format:

 

function is_email($email)
{
    $formatTest = '/^[\w!#$%&\'*+\-\/=?^`{|}~]+(\.[\w!#$%&\'*+\-\/=?^`{|}~]+)*@[a-z\d]([a-z\d-]*[a-z\d])?(\.[a-z\d]([a-z\d-]*[a-z\d])?)*\.[a-z]{2,6}$/i';
    $lengthTest = '/^(.{1,64})@(.{4,255})$/';
    return (preg_match($formatTest, $email) && preg_match($lengthTest, $email));
} 

 

Here are the details of the exact validation properties:

// NOTES:
//
// Format test
// - Username:
//     - Can contain the following characters: 
//         - Uppercase and lowercase English letters (a-z, A-Z) 
//         - Digits 0 to 9 
//         - Characters _ ! # $ % & ' * + - / = ? ^ ` { | } ~ 
//     - May contain '.' (periods), but cannot begin or end with a period
//       and they may not appear in succession (i.e. 2 or more in a row) 
//     - Must be between 1 and 64 characters 
// - Domain:
//     - Can contain the following characters: 'a-z', 'A-Z', '0-9', and '-' (hyphen). 
//     - There may be subdomains, separated by a period (.), but the combined domain may not begin with a period
//       and they not appear in succession (i.e. 2 or more in a row) 
//     - Hostname parts may not begin or end with a hyphen 
// - TLD accepts: 'a-z' & 'A-Z'
//
// Note: the domain and tld parts must be between 4 and 256 characters total 
//
// Length test
// - Username: 1 to 64 characters
// - Domain: 4 to 255 character