PHP的filter_var FILTER_VALIDATE_EMAIL实际上有效吗?

31
在阅读了各种帖子后,我决定不使用REGEX来检查电子邮件是否有效,而是直接使用PHP内置的filter_var函数。它似乎工作得很好,直到它告诉我一个电子邮件无效,因为我其中有一个数字。
例如:name@domain.com可以正常工作,而name2@domain.com则不行。
我是否遗漏了什么或者filter_var($email, FILTER_VALIDATE_EMAIL)真的相当无效吗?

测试电子邮件地址中是否存在点也是必要的。http://www.electrictoolbox.com/php-email-validation-filter-var-updated/ - Istiaque Ahmed
1
@willdanceforfun,你的问题不准确。在所有支持filter_var()函数的PHP版本中,name2@domain.com都可以正常工作。证明链接:http://3v4l.org/joLvm - Brad
4个回答

34

PHP 5.3.3 过滤器代码中使用的正则表达式基于Michael Rushton关于 电子邮件地址验证 的博客。它似乎可以处理您提到的情况。

您还可以查看比较电子邮件地址验证正则表达式 中的一些选项(PHP当前使用的正则表达式是其中之一)

然后您可以选择自己喜欢的正则表达式,并在调用preg_match()时使用它。

或者,您可以取代PHP/ext/filter/logical_filter.c文件中的正则表达式,函数为php_filter_validate_email(),并重新构建PHP。


Michael Rushton的博客链接现在带您进入了一个空白页面:( - Matteo
@Matteo,你可以在PHP源代码中找到相同的代码。或者在Wayback Machine中找到Michael Rushton的博客:https://web.archive.org/web/20150910045413/http://squiloople.com/2009/12/20/email-address-validation - Bill Karwin

5

name2@domain.com 看起来很正常:http://codepad.org/5HDgMW5i

但是我确实看到人们抱怨它存在问题,甚至在SO上也是如此。很可能它确实存在问题,但是使用正则表达式的解决方案也会有问题。电子邮件地址规范非常复杂(RFC XXXX)。

这就是为什么验证电子邮件的唯一解决方案是向该地址发送电子邮件并要求采取行动(例如:如果它是注册脚本,请要求他们单击验证链接)。


谢谢。我将发送一封验证电子邮件,只是希望有一些措施确保人们不会意外地添加明显错误的字符。 - willdanceforfun
3
@Keen 我并不是说完全放弃使用正则表达式进行验证;你可以对它进行验证,如果验证失败就警告用户(例如:“计算机说您的电子邮件地址无效,但它并不是很聪明。 您确定要使用此电子邮件地址吗?”)。 - NullUserException

2
function isValidEmail($email, $checkDNS = false)
{

    $valid = (
            /* Preference for native version of function */
            function_exists('filter_var') and filter_var($email, FILTER_VALIDATE_EMAIL)
            ) || (
                /* The maximum length of an e-mail address is 320 octets, per RFC 2821. */
                strlen($email) <= 320
                /*
                 * The regex below is based on a regex by Michael Rushton.
                 * However, it is not identical. I changed it to only consider routeable
                 * addresses as valid. Michael's regex considers a@b a valid address
                 * which conflicts with section 2.3.5 of RFC 5321 which states that:
                 *
                 * Only resolvable, fully-qualified domain names (FQDNs) are permitted
                 * when domain names are used in SMTP. In other words, names that can
                 * be resolved to MX RRs or address (i.e., A or AAAA) RRs (as discussed
                 * in Section 5) are permitted, as are CNAME RRs whose targets can be
                 * resolved, in turn, to MX or address RRs. Local nicknames or
                 * unqualified names MUST NOT be used.
                 *
                 * This regex does not handle comments and folding whitespace. While
                 * this is technically valid in an email address, these parts aren't
                 * actually part of the address itself.
                 */
                and preg_match_all(
                    '/^(?!(?:(?:\\x22?\\x5C[\\x00-\\x7E]\\x22?)|(?:\\x22?[^\\x5C\\x22]\\x22?))'.
                    '{255,})(?!(?:(?:\\x22?\\x5C[\\x00-\\x7E]\\x22?)|(?:\\x22?[^\\x5C\\x22]\\x22?))'.
                    '{65,}@)(?:(?:[\\x21\\x23-\\x27\\x2A\\x2B\\x2D\\x2F-\\x39\\x3D\\x3F\\x5E-\\x7E]+)|'.
                    '(?:\\x22(?:[\\x01-\\x08\\x0B\\x0C\\x0E-\\x1F\\x21\\x23-\\x5B\\x5D-\\x7F]|(?:\\x5C[\\x00-\\x7F]))*\\x22))'.
                    '(?:\\.(?:(?:[\\x21\\x23-\\x27\\x2A\\x2B\\x2D\\x2F-\\x39\\x3D\\x3F\\x5E-\\x7E]+)|'.
                    '(?:\\x22(?:[\\x01-\\x08\\x0B\\x0C\\x0E-\\x1F\\x21\\x23-\\x5B\\x5D-\\x7F]|'.
                    '(?:\\x5C[\\x00-\\x7F]))*\\x22)))*@(?:(?:(?!.*[^.]{64,})'.
                    '(?:(?:(?:xn--)?[a-z0-9]+(?:-+[a-z0-9]+)*\\.){1,126})'.'{1,}'.
                    '(?:(?:[a-z][a-z0-9]*)|(?:(?:xn--)[a-z0-9]+))(?:-+[a-z0-9]+)*)|'.
                    '(?:\\[(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){7})|'.
                    '(?:(?!(?:.*[a-f0-9][:\\]]){7,})(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?::'.
                    '(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,5})?)))|'.
                    '(?:(?:IPv6:(?:(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){5}:)|'.
                    '(?:(?!(?:.*[a-f0-9]:){5,})'.'(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3})?::'.
                    '(?:[a-f0-9]{1,4}(?::[a-f0-9]{1,4}){0,3}:)?)))?(?:(?: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}))\\]))$/iD',
                    $email)
            );

    if( $valid )
    {
        if( $checkDNS && ($domain = end(explode('@',$email, 2))) )
        {
            /*
            Note:
            Adding the dot enforces the root.
            The dot is sometimes necessary if you are searching for a fully qualified domain
            which has the same name as a host on your local domain.
            Of course the dot does not alter results that were OK anyway.
            */
            return checkdnsrr($domain . '.', 'MX');
        }
        return true;
    }
    return false;
}


//-----------------------------------------------------------------

    var_dump(isValidEmail('nechtan@tagon8inc.com', true));
    // bool(true)

1

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