What's the easy way to test for 304 reponses?

I need to test if my 304 responses are working, but my development environment is pretty hard set on force no-cache.

Is there an easy way to modify the max-age value of the cache-control header before it goes out?

I'm perhaps a bit optimistic in hoping chrome (or an exte开发者_如何学Cnsion, or FF) has a console command letting me alter the if-modified-since header then send the request. Maybe paste something into a telnet connection?

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If you have access to curl, the easy way is:

curl -H "If-Modified-Since: Sat, 15 May 2010 12:06:39 GMT" -i http://www.wikipedia.org | grep "HTTP/"

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You could use tamper data - its a firefox plugin that allows you to modify request headers. See https://addons.mozilla.org/en-US/firefox/addon/966/