HTTP validation utilities?

Does anyone know of a utility开发者_如何学Python that can check whether a HTTP request/response is valid?

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Fiddler: http://www.fiddler2.com/fiddler2/

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Wireshark (used to be known as Ethereal).

http://www.wireshark.org/

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Something like HTTP Analyzer?

ps. It's a non-free tool, but I'm in no way affiliated.