Updating valid_email() helper function.

helpers/MY_email_helper.php

@@ -2,19 +2,97 @@
 
 if (!function_exists('valid_email')) {
 
-    function valid_email($email) {
+    // This function has been borrowed from PHPMailer Version 5.2.7.
+    /**
+     * Check that a string looks like an email address.
+     * @param string $address The email address to check
+     * @param string $patternselect A selector for the validation pattern to use :
+     *   'auto' - pick best one automatically;
+     *   'pcre8' - use the squiloople.com pattern, requires PCRE > 8.0, PHP >= 5.3.2, 5.2.14;
+     *   'pcre' - use old PCRE implementation;
+     *   'php' - use PHP built-in FILTER_VALIDATE_EMAIL; faster, less thorough;
+     *   'noregex' - super fast, really dumb.
+     * @return bool
+     * @static
+     * @access public
+     */
+    // Modified by Ivan Tcholakov, 24-DEC-2013.
+    //public static function validateAddress($address, $patternselect = 'auto')
+    //{
+    function valid_email($address) {
+        $patternselect = 'auto';
+    //
 
-        static $filter_var_exists;
-
-        if (!isset($filter_var_exists)) {
-            $filter_var_exists = function_exists('filter_var');
+        if ($patternselect == 'auto') {
+            if (defined(
+                'PCRE_VERSION'
+            )
+            ) { //Check this instead of extension_loaded so it works when that function is disabled
+                if (version_compare(PCRE_VERSION, '8.0') >= 0) {
+                    $patternselect = 'pcre8';
+                } else {
+                    $patternselect = 'pcre';
+                }
+            } else {
+                //Filter_var appeared in PHP 5.2.0 and does not require the PCRE extension
+                if (version_compare(PHP_VERSION, '5.2.0') >= 0) {
+                    $patternselect = 'php';
+                } else {
+                    $patternselect = 'noregex';
+                }
+            }
         }
-
-        if ($filter_var_exists) {
-            return (bool) filter_var($email, FILTER_VALIDATE_EMAIL);
+        switch ($patternselect) {
+            case 'pcre8':
+                /**
+                 * Conforms to RFC5322: Uses *correct* regex on which FILTER_VALIDATE_EMAIL is
+                 * based; So why not use FILTER_VALIDATE_EMAIL? Because it was broken to
+                 * not allow a@b type valid addresses :(
+                 * @link http://squiloople.com/2009/12/20/email-address-validation/
+                 * @copyright 2009-2010 Michael Rushton
+                 * Feel free to use and redistribute this code. But please keep this copyright notice.
+                 */
+                return (bool)preg_match(
+                    '/^(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){255,})(?!(?>(?1)"?(?>\\\[ -~]|[^"])"?(?1)){65,}@)' .
+                    '((?>(?>(?>((?>(?>(?>\x0D\x0A)?[\t ])+|(?>[\t ]*\x0D\x0A)?[\t ]+)?)(\((?>(?2)' .
+                    '(?>[\x01-\x08\x0B\x0C\x0E-\'*-\[\]-\x7F]|\\\[\x00-\x7F]|(?3)))*(?2)\)))+(?2))|(?2))?)' .
+                    '([!#-\'*+\/-9=?^-~-]+|"(?>(?2)(?>[\x01-\x08\x0B\x0C\x0E-!#-\[\]-\x7F]|\\\[\x00-\x7F]))*' .
+                    '(?2)")(?>(?1)\.(?1)(?4))*(?1)@(?!(?1)[a-z0-9-]{64,})(?1)(?>([a-z0-9](?>[a-z0-9-]*[a-z0-9])?)' .
+                    '(?>(?1)\.(?!(?1)[a-z0-9-]{64,})(?1)(?5)){0,126}|\[(?:(?>IPv6:(?>([a-f0-9]{1,4})(?>:(?6)){7}' .
+                    '|(?!(?:.*[a-f0-9][:\]]){8,})((?6)(?>:(?6)){0,6})?::(?7)?))|(?>(?>IPv6:(?>(?6)(?>:(?6)){5}:' .
+                    '|(?!(?:.*[a-f0-9]:){6,})(?8)?::(?>((?6)(?>:(?6)){0,4}):)?))?(25[0-5]|2[0-4][0-9]|1[0-9]{2}' .
+                    '|[1-9]?[0-9])(?>\.(?9)){3}))\])(?1)$/isD',
+                    $address
+                );
+                break;
+            case 'pcre':
+                //An older regex that doesn't need a recent PCRE
+                return (bool)preg_match(
+                    '/^(?!(?>"?(?>\\\[ -~]|[^"])"?){255,})(?!(?>"?(?>\\\[ -~]|[^"])"?){65,}@)(?>' .
+                    '[!#-\'*+\/-9=?^-~-]+|"(?>(?>[\x01-\x08\x0B\x0C\x0E-!#-\[\]-\x7F]|\\\[\x00-\xFF]))*")' .
+                    '(?>\.(?>[!#-\'*+\/-9=?^-~-]+|"(?>(?>[\x01-\x08\x0B\x0C\x0E-!#-\[\]-\x7F]|\\\[\x00-\xFF]))*"))*' .
+                    '@(?>(?![a-z0-9-]{64,})(?>[a-z0-9](?>[a-z0-9-]*[a-z0-9])?)(?>\.(?![a-z0-9-]{64,})' .
+                    '(?>[a-z0-9](?>[a-z0-9-]*[a-z0-9])?)){0,126}|\[(?:(?>IPv6:(?>(?>[a-f0-9]{1,4})(?>:' .
+                    '[a-f0-9]{1,4}){7}|(?!(?:.*[a-f0-9][:\]]){8,})(?>[a-f0-9]{1,4}(?>:[a-f0-9]{1,4}){0,6})?' .
+                    '::(?>[a-f0-9]{1,4}(?>:[a-f0-9]{1,4}){0,6})?))|(?>(?>IPv6:(?>[a-f0-9]{1,4}(?>:' .
+                    '[a-f0-9]{1,4}){5}:|(?!(?:.*[a-f0-9]:){6,})(?>[a-f0-9]{1,4}(?>:[a-f0-9]{1,4}){0,4})?' .
+                    '::(?>(?:[a-f0-9]{1,4}(?>:[a-f0-9]{1,4}){0,4}):)?))?(?>25[0-5]|2[0-4][0-9]|1[0-9]{2}' .
+                    '|[1-9]?[0-9])(?>\.(?>25[0-5]|2[0-4][0-9]|1[0-9]{2}|[1-9]?[0-9])){3}))\])$/isD',
+                    $address
+                );
+                break;
+            case 'php':
+            default:
+                return (bool)filter_var($address, FILTER_VALIDATE_EMAIL);
+                break;
+            case 'noregex':
+                //No PCRE! Do something _very_ approximate!
+                //Check the address is 3 chars or longer and contains an @ that's not the first or last char
+                return (strlen($address) >= 3
+                    and strpos($address, '@') >= 1
+                    and strpos($address, '@') != strlen($address) - 1);
+                break;
         }
-
-        return (bool) preg_match('/^(?:[\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_]?)|(?:\[(?:(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\]))$/', $email);
     }
 
 }