浏览器检测

var client = function(){ 
 
    //呈现引擎 
    var engine = {             
        ie: 0, 
        gecko: 0, 
        webkit: 0, 
        khtml: 0, 
        opera: 0, 
     
        //完整的版本号 
        ver: null   
    }; 
 
    //浏览器 
    var browser = { 
         
        //主要浏览器 
        ie: 0, 
        firefox: 0, 
        safari: 0, 
        konq: 0, 
        opera: 0, 
       chrome: 0, 
     
        //具体的版本号 
        ver: null 
    }; 
 
 
    //平台、设备和操作系统 
    var system = { 
        win: false, 
        mac: false, 
        x11: false, 
         
        //移动设备 
        iphone: false, 
        ipod: false, 
        ipad: false, 
        ios: false, 
        android: false, 
        nokiaN: false, 
        winMobile: false, 
         
        //游戏系统 
        wii: false, 
        ps: false  
    };     
     
    //检测呈现引擎和浏览器 
    var ua = navigator.userAgent;     
    if (window.opera){ 
        engine.ver = browser.ver = window.opera.version(); 
        engine.opera = browser.opera = parseFloat(engine.ver); 
    } else if (/AppleWebKit/(S+)/.test(ua)){ 
        engine.ver = RegExp["$1"]; 
        engine.webkit = parseFloat(engine.ver); 
         
        //确定是 Chrome 还是 Safari 
        if (/Chrome/(S+)/.test(ua)){ 
            browser.ver = RegExp["$1"]; 
            browser.chrome = parseFloat(browser.ver); 
        } else if (/Version/(S+)/.test(ua)){ 
            browser.ver = RegExp["$1"]; 
            browser.safari = parseFloat(browser.ver); 
        } else { 
            //近似地确定版本号 
            var safariVersion = 1; 
            if (engine.webkit < 100){ 
                safariVersion = 1; 
            } else if (engine.webkit < 312){ 
                safariVersion = 1.2; 
            } else if (engine.webkit < 412){ 
                safariVersion = 1.3; 
            } else { 
                safariVersion = 2; 
            }    
             
            browser.safari = browser.ver = safariVersion;         
        }

} else if (/KHTML/(S+)/.test(ua) || /Konqueror/([^;]+)/.test(ua)){ 
        engine.ver = browser.ver = RegExp["$1"]; 
        engine.khtml = browser.konq = parseFloat(engine.ver); 
    } else if (/rv:([^)]+)) Gecko/d{8}/.test(ua)){     
        engine.ver = RegExp["$1"]; 
        engine.gecko = parseFloat(engine.ver); 
         
        //确定是不是 Firefox 
        if (/Firefox/(S+)/.test(ua)){ 
            browser.ver = RegExp["$1"]; 
            browser.firefox = parseFloat(browser.ver); 
        } 
    } else if (/MSIE ([^;]+)/.test(ua)){     
        engine.ver = browser.ver = RegExp["$1"]; 
        engine.ie = browser.ie = parseFloat(engine.ver); 
    } 
 
    //检测浏览器 
    browser.ie = engine.ie; 
    browser.opera = engine.opera; 
 
 
    //检测平台 
    var p = navigator.platform; 
    system.win = p.indexOf("Win") == 0; 
    system.mac = p.indexOf("Mac") == 0; 
    system.x11 = (p == "X11") || (p.indexOf("Linux") == 0); 
 
    //检测 Windows 操作系统 
    if (system.win){ 
        if (/Win(?:dows )?([^do]{2})s?(d+.d+)?/.test(ua)){ 
            if (RegExp["$1"] == "NT"){ 
                switch(RegExp["$2"]){ 
                    case "5.0": 
                        system.win = "2000"; 
                        break; 
                    case "5.1": 
                        system.win = "XP"; 
                        break; 
                    case "6.0": 
                        system.win = "Vista"; 
                        break; 
                    case "6.1": 
                        system.win = "7"; 
                        break; 
                    default: 
                        system.win = "NT"; 
                        break;                 
                }                             
            } else if (RegExp["$1"] == "9x"){ 
                system.win = "ME"; 
            } else { 
                system.win = RegExp["$1"]; 
            } 
        } 
    } 
 
    //移动设备 
    system.iphone = ua.indexOf("iPhone") > -1; 
   system.ipod = ua.indexOf("iPod") > -1; 
   system.ipad = ua.indexOf("iPad") > -1; 
   system.nokiaN = ua.indexOf("NokiaN") > -1; 
 
   //windows mobile 
 
if (system.win == "CE"){ 
 
 
 system.winMobile = system.win; 
 
} else if (system.win == "Ph"){ 
 
 
 if(/Windows Phone OS (d+.d+)/.test(ua)){; 
 
    system.win = "Phone"; 
 
   system.winMobile = parseFloat(RegExp["$1"]); 
 
   } 
 
} 
 
 
 
//检测 iOS 版本 
 
if (system.mac && ua.indexOf("Mobile") > -1){ 
 
 
if (/CPU (?:iPhone )?OS (d+_d+)/.test(ua)){ 
 
    system.ios = parseFloat(RegExp.$1.replace("_", ".")); 
 
 
} else { 
 
   system.ios = 2; //不能真正检测出来，所以只能猜测 
 
 
} 
 
} 
 
 
//检测 Android 版本 
 
if (/Android (d+.d+)/.test(ua)){ 
 
 
 system.android = parseFloat(RegExp.$1); 
 
} 
 
    //游戏系统 
    system.wii = ua.indexOf("Wii") > -1; 
    system.ps = /playstation/i.test(ua); 
 
    //返回这些对象 
    return { 
        engine:     engine, 
        browser:    browser, 
        system:     system         
    }; 
 
}();