jquery uaMatch源代码

// Useragent RegExp
rwebkit = /(webkit)[ //]([/w.]+)/,
ropera = /(opera)(?:.*version)?[ //]([/w.]+)/,
rmsie = /(msie) ([/w.]+)/,
rmozilla = /(mozilla)(?:.*? rv:([/w.]+))?/,
// Keep a UserAgent string for use with jQuery.browser
userAgent = navigator.userAgent,

// For matching the engine and version of the browser
browserMatch,

// Use of jQuery.browser is frowned upon.
// More details: http://docs.jquery.com/Utilities/jQuery.browser
uaMatch: function( ua ) {
ua = ua.toLowerCase();

var match = rwebkit.exec( ua ) ||
ropera.exec( ua ) ||
rmsie.exec( ua ) ||
ua.indexOf("compatible") < 0 && rmozilla.exec( ua ) ||
[];

return { browser: match[1] || "", version: match[2] || "0" };
}
browserMatch = jQuery.uaMatch( userAgent );
if ( browserMatch.browser ) {
jQuery.browser[ browserMatch.browser ] = true;
jQuery.browser.version = browserMatch.version;
}