get_browser() attempts to determine the capabilities of the user's browser. This is done by looking up the browser's information in the browscap.ini file. By default, the value of $_SERVER["HTTP_USER_AGENT"] is used; however, you can alter this (i.e., look up another browser's info) by passing the optional user_agent parameter to get_browser().
The information is returned in an object, which will contain various data elements representing, for instance, the browser's major and minor version numbers and ID string; TRUE/FALSE values for features such as frames, JavaScript, and cookies; and so forth.
While browscap.ini contains information on many browsers, it relies on user updates to keep the database current. The format of the file is fairly self-explanatory.
The following example shows how one might list all available information retrieved about the user's browser.
In order for this to work, your browscap configuration setting in php.ini must point to the correct location of the browscap.ini file on your system. browscap.ini is not bundled with PHP but you may find an up-to-date browscap.ini file here. By default, the browscap directive is commented out.
The cookies value simply means that the browser itself is capable of accepting cookies and does not mean the user has enabled the browser to accept cookies or not. The only way to test if cookies are accepted is to set one with setcookie(), reload, and check for the value.
注: On versions older than PHP 4.0.6, you will have to pass the user agent in via the optional user_agent parameter if the PHP directive register_globals is off. In this case, you will pass in $HTTP_SERVER_VARS['HTTP_USER_AGENT'].