What is the best way to distinguish on a server between a request that came from an iPhone through the web browser vs through an iphone with an app written in objective c? What differences do I look for in the user agent string?
I believe user agents from the Safari app start with "Mozilla", while user agents from apps start with the name of the app.
It seems that iPhone Apps using the UIWebKit HTTP request component have user agent string like the following
Mozilla/5.0 (iPhone; U; CPU iPhone OS 4_0_1 like Mac OS X; fr-fr) AppleWebKit/532.9 (KHTML, like Gecko) Mobile/8A306
Mozilla/5.0 (iPhone; U; CPU iPhone OS 3_1_2 like Mac OS X; fr-fr) AppleWebKit/528.18 (KHTML, like Gecko) Mobile/7D11
Mozilla/5.0 (iPhone; U; CPU iPhone OS 3_1_3 like Mac OS X; fr-fr) AppleWebKit/528.18 (KHTML, like Gecko) Mobile/7E18
While Safari on iPhone has mostly the same string but ending with " Safari/XXX"
However, it is also possible to change the user agent of UIWebKit then there is no guarantee that you'll grab every iPhone app by proceeding this way.
Indeed the user agent will be different.
in PHP, you can find out with this: $_SERVER['HTTP_USER_AGENT']
来源：https://stackoverflow.com/questions/3305867/distinguish-between-iphone-web-browser-and-iphone-app-user-agent