【javascript】浏览器用户代理检测脚本实现

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Chroeme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 (?:Phone )?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
};

// console.log(engine);
//  console.log(browser);
//  console.log(system);
}();