php - 为什么 filter_var($email, FILTER_VALIDATE_EMAIL) 允许 test@test？

Question

我刚刚为一个表单设置验证，我决定尝试使用 filter_var 函数来检查我的电子邮件地址的有效性。我无法找出 filter_var 在任何地方实际允许的内容(因为文档非常简单)，而且我发现它允许像 test@test 这样的电子邮件地址。域中是否必须有 .com、.net 等？

Answer 1

行为在 4 月左右发生了变化。参见 bug #49576和 revision 297350 .

该电子邮件确实无效，或者至少 PHP 开发人员是这样理解的。消息来源带有此通知:

/*
 * 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.

changelog提到了针对 PHP 5.3.3 和 PHP 5.2.14 的错误修复。