有效電子郵件地址的正則表達式？

Question

準確重複：Using a regular expression to validate an email address

什麼是有效的電子郵件地址字符和模式，以及如何編寫與之匹配的正則表達式？

Answer 1

在這裏你去：

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\t]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\0 
31]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\ 
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)*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\ 
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\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:(?: 
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*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t]) 
+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\ 
.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \000-\031]+(?:(?:(?:\r\n)?[ \t])+|\Z 
|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*\>(?:(
?:\r\n)?[ \t])*))*)?;\s*) 

不，我不是在開玩笑。 http://www.ex-parrot.com/~pdw/Mail-RFC822-Address.html

Answer 2

這是一個良好的開端：

http://www.regular-expressions.info/email.html

作爲一個側面說明，這個網站可能是開始對正則表達式的幫助和教程的最佳場所。

Answer 3

簡短的回答是：它很複雜。

我曾經遇到過的電子郵件驗證的最完整和準確的正則表達式是here。這不是因爲心靈的模糊;它足夠複雜，它被分解成多個部分，以便人們更容易解析（示例代碼是用Java編寫的）。但是，如果一切順利進行驗證是值得的，我認爲它不會好得多。

請記住，specification提到了許多可能不被認爲是電子郵件地址的典型情況。你可能想知道它們，並決定這些情況對你是否重要。

無論如何，我建議您使用單元測試來確認您的表達涵蓋了您認爲重要的情況。這樣，當你對它進行干涉時，你可以確定你沒有破壞一些以前工作過的情況。