JS笔记：检测客户端（引擎、浏览器、平台、操作系统、移动设备）

首先需要取得用户代理字符串
如chrome：mozilla/5.0 (windows; u; windows nt 5.1; en-us) applewebkit/534.7 (khtml, like gecko) chrome/7.0.517.44 safari/534.7

//取得用户代理字符串 并全部小写。
var ua = navigator.userAgent.toLowerCase();
document.write(ua);

1、识别呈现引擎
引擎主要包含四种：IE、Gecko、WebKit、Opera

2、识别浏览器
主流浏览器包含四种：IE、Chrome、Firefox、Opera

3、识别平台
主流平台包含三类：Windows、Mac、Unix

4、识别Windows操作系统
Windows操作系统包含：Windows 98、Window NT、Window XP、Window Vista、Windows 7…

5、识别移动设备
主流的移动设备包含三类：iPhone、iPod、Anroid、Nokia

6、识别游戏系统。
主流的游戏系统包含两类：Wii、PS3。

网上发现的比较简单的区分代码：

var ua = navigator.userAgent.toLowerCase();
var isStrict = document.compatMode == "CSS1Compat"
isOpera = ua.indexOf("opera") > -1
isChrome = ua.indexOf("chrome") > -1
isSafari = !isChrome && (/webkit|khtml/).test(ua)
isSafari3 = isSafari && ua.indexOf('webkit/5') != -1
isIE = !isOpera && ua.indexOf("msie") > -1
isIE7 = !isOpera && ua.indexOf("msie 7") > -1
isIE8 = !isOpera && ua.indexOf("msie 8") > -1
isGecko = !isSafari && !isChrome && ua.indexOf("gecko") > -1
isGecko3 = isGecko && ua.indexOf("rv:1.9") > -1
isBorderBox = isIE && !isStrict

isWin7 = ua.indexOf("nt 6.1") > -1
isVista = ua.indexOf("nt 6.0") > -1
isWin2003 = ua.indexOf("nt 5.2") > -1
isWinXp = ua.indexOf("nt 5.1") > -1
isWin2000 = ua.indexOf("nt 5.0") > -1
isWindows = (ua.indexOf("windows") != -1 || ua.indexOf("win32") != -1)
isMac = (ua.indexOf("macintosh") != -1 || ua.indexOf("mac os x") != -1)
isAir = (ua.indexOf("adobeair") != -1)
isLinux = (ua.indexOf("linux") != -1)

var sys = "";
var broser = "";

if(isIE){
broser = "IE 6";
}else if(isIE7){
broser = "IE 7";
}else if(isIE8){
broser = "IE 8";
}else if(isOpera){
broser = "Opera";
}else if(isChrome){
broser = "Chrome";
}else if(isSafari){
broser = "Safari";
}else if(isSafari3){
broser = "Safari3";
}else{
broser = "Unknow";
}

if(isWin7){
sys = "Windows 7";
}else if(isVista){
sys = "Vista";
}else if(isWinXp){
sys = "Windows xp";
}else if(isWin2003){
sys = "Windows 2003";
}else if(isWin2000){
sys = "Windows 2000";
}else if(isWindows){
sys = "Windows";
}else if(isMac){
sys = "Macintosh";
}else if(isAir){
sys = "Adobeair";
}else if(isLinux){
sys = "Linux";
}else{
sys = "Unknow";
}
document.write(ua);
alert(sys + ":" + broser);

比较全面的区分代码：

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,
	konq: 0,
	opera : 0,
	chrome: 0,
	safari: 0,
 
	//具体的版本号
	ver : null
};
 
//平台、设备和操作系统
var system ={
	win : false,
	mac : false,
	xll : false,
 
	//移动设备
	iphone: false,
	ipod: false,
	nokiaN: false,
	winMobile : false,
	macMobile : false,
 
	//游戏设备
	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) || /Konquersor\/([^;]+)/.test(ua)){
	engine.ver = browser.ver = RegExp["$1"];
	engine.khtml = browser.kong = paresFloat(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 = pareseFloat(browser.ver);
	}
} else if(/MSIE([^;]+)/.test(ua)){
		browser.ver = RegExp["$1"];
		browser.firefox = parseFloat(browser.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(?:doms)?([^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;
				default :
					system.win = "NT";
					break;				
			}
		} else if (RegExp["$1"]){
			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.nokiaN	 = ua.indexOf("NokiaN") > -1;
system.winMobile = (system.win == "CE");
system.macMobile = (system.iphone || system.ipod);
//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
};
}()