JavaScript client detection technology-JS Tutorial-php.cn

　1. Firefox

Gecko is the rendering engine of firefox. Gecko was originally developed as part of the general Mozilla browser, and the first browser to use the Gecko engine was Netscape6;

We can use the user agent to detect: The following JS code:

var ua = navigator.userAgent;
console.log(ua);

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The printing under firefox under windows is as follows:

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0

The above is the proxy string written for Netscape6 Some components: as follows:

Mozilla/Mozilla version number (platform; encryption type; operating system or CPU; pre-release version; Gecko/Gecko version number; application or product/application or product version number) ；

　2. Safari

Safari’s rendering engine is WebKit; it is a branch of KHTML, the rendering engine of the Konqueror browser in the Linux platform; a few years later, webkit became independent It became an open source project, focusing on rendering engine development;

The following code:

var ua = navigator.userAgent;
console.log(ua);

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Printed under safari under windows as follows:

Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.57.2 (KHTML, like Gecko) Version/5.1.7 Safari/534.57.2

The user agent string of Webkit has the following format:

Mozilla/5.0 (Platform ; Encryption type; operating system or cpu) AppleWebkit/AppleWebkit version number (KHTML, like Gecko) safari/safari version number;

　3. Chrome

　 Google's The chrome browser uses webkit as the rendering engine and uses different javascript engines;

The following JS code:

var ua = navigator.userAgent;
console.log(ua);

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The print under chrome under windows is as follows:

Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/42.0.2311.152 Safari/537.36

The user agent string is completely taken from webkit, and only a section indicating the chrome version number information is added; format As follows:

Mozilla/5.0 (platform; encryption type; operating system or cpu) AppleWebKit/AppleWebKit version number (KHTML, like Gecko) chrome/chrome version number safari/safari version number

　4. Opera

Opera’s default user agent string is the most reasonable of all modern browsers---it correctly identifies itself and its version number. Before Opera8.0; its users The proxy string adopts the following format:

Opera/ version number (operating system or CPU; encryption type) [language]

After the release of Opera 8, the "language" part of the user agent string was moved to parentheses to better match other browsers; as follows:

Opera/version number (operating system or CPU; encryption type; language)

In the latest version now The version of opera29,

The following JS code:

var ua = navigator.userAgent;
console.log(ua);

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The proxy detection is as follows:

Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko ) Chrome/42.0.2311.152 Safari/537.36 OPR/29.0.1795.60；

　5. IE

Since IE3, Microsoft has modified the user agent string of IE Into a form compatible with Netscape, the structure is as follows:

Mozilla/version number (platform; encryption type; operating system or CPU);

However, the user agent string of IE8+ adds the rendering engine's ( Trident) version number;

The JS code is as follows:

var ua = navigator.userAgent.toLowerCase();
console.log(ua);

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For example, the version number of IE7 under window is as follows:

mozilla/4.0 (compatible; msie 7.0; windows nt 6.1; wow64; trident/7.0; slcc2; .net clr 2.0.50727; .net clr 3.5.30729; .net clr 3.0.30729; media center pc 6.0; infopath.3; .net4.0c; .net4.0e)

IE8 is as follows:

mozilla/4.0 (compatible; msie 8.0; windows nt 6.1; wow64; trident/7.0; slcc2; .net clr 2.0.50727; .net clr 3.5.30729; . net clr 3.0.30729; media center pc 6.0; infopath.3; .net4.0c; .net4.0e)

　However, IE9+ has made some adjustments to the string format; mozilla’s version number has been increased to 5.0 ;

IE9 is as follows:

mozilla/5.0 (compatible; msie 9.0; windows nt 6.1; wow64; trident/7.0; slcc2; .net clr 2.0.50727; .net clr 3.5. 30729; .net clr 3.0.30729; media center pc 6.0; infopath.3; .net4.0c; .net4.0e)

IE10 is as follows:

mozilla/5.0 (compatible; msie 10.0; windows nt 6.1; wow64; trident/7.0; slcc2; .net clr 2.0.50727; .net clr 3.5.30729; .net clr 3.0.30729; media center pc 6.0; infopath.3; .net4.0c; .net4.0e)

IE11 is as follows:

mozilla/5.0 (windows nt 6.1; wow64; trident/7.0; slcc2; .net clr 2.0.50727; .net clr 3.5.30729 ; .net clr 3.0.30729; media center pc 6.0; infopath.3; .net4.0c; .net4.0e; rv:11.0) like gecko

　6. IOS and Android

The default browsers of mobile operating systems IOS and Android are based on webkit; and they are both like the desktop version; they share the same basic user agent string format; the basic format of ios devices is as follows:

Mozilla/5.0 (Platform; encryption type; operating system or CPU like Mac OS x; language)

AppleWebKit/ AppleWebKit version number (KHTML, like Gecko) Version/browser version number

Mobile/Mobile version numberSafari/Safari version number

　　Android浏览器中默认格式与IOS格式相似，没有移动版本号(但有Mobile记号)：

　　Mozilla/5.0 (Linux; U; Android 2.2; en-us; Nexus One Build/FRF91)

　　AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1

　　7. Konqueror

　　与KDE Linux 集成的Konqueror，是一款基于KHTML 开源呈现引擎的浏览器。尽管Konqueror 只

　　能在Linux 中使用，但它也有数量可观的用户。为确保最大限度的兼容性，Konqueror 效仿IE 选择了如

　　下用户代理字符串格式：

　　Mozilla/5.0 (compatible; Konqueror/ 版本号; 操作系统或CPU )

　　不过，为了与WebKit 的用户代理字符串的变化保持一致，Konqueror 3.2 又有了变化，以如下格式

　　将自己标识为KHTML：

　　Mozilla/5.0 (compatible; Konqueror/ 版本号; 操作系统或CPU) KHTML/ KHTML 版本号 (like Gecko)

　　下面是一个例子：

　　Mozilla/5.0 (compatible; Konqueror/3.5; SunOS) KHTML/3.5.0 (like Gecko)

　　用户代理字符串检测技术

　　识别呈现引擎；

　　下面我们主要检测五大呈现引擎：IE，Gecko，WebKit，KHTML和Opera

　　如下代码：

var client = function(){
    var engine = {
        // 呈现引擎
        ie: 0,
        gecko:0,
        webkit: 0,
        khtml:0,
        opera:0,
        //其他版本号
        ver: null
    };
    // 在此检测呈现引擎，平台和设备
    return {
        engine: engine
    };
}();

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　　在如上client对象字面量中，每个呈现引擎都对应着一个属性，属性值默认为0；如果检测到了那个呈现引擎，那么将以浮点数值形式将引擎的版本号写入相应的属性。而呈现引擎的完整版本被写入变量ver属性中；

　　要正确识别呈现引擎，关键是检测顺序要正确，用户代理字符串存在诸多不一致的地方，如果检测顺序不对，很可能会导致检测结果不正确，因此，第一步就是识别Opera，因为它的用户代理字符串有可能模仿其他浏览器；目前最新的opera浏览器版本是29，所以如下：

　var ua = navigator.userAgent .toLowerCase();
　　console.log(ua);

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　　打印如下：

　　mozilla/5.0 (windows nt 6.1; wow64) applewebkit/537.36 (khtml, like gecko) chrome/42.0.2311.152 safari/537.36 opr/29.0.1795.60

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　　因此可以这样判断代码；如下：

var ua = navigator.userAgent.toLowerCase();
if(ua.match(/opr\/([\d\.]+)/)) {
    var result = ua.match(/opr\/([\d\.]+)/);
    console.log(result)
    console.log(result[1])
}

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　　执行如下：

　　console.log(result);打印如下：

　　["opr/29.0.1795.60", "29.0.1795.60", index: 110, input: "mozilla/5.0 (windows nt 6.1; wow64) applewebkit/53…rome/42.0.2311.152 safari/537.36 opr/29.0.1795.60"]；

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　　console.log(result[1])打印如下：

　　29.0.1795.60

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　　由此；我们可以这样编写代码；如下：

var ua = navigator.userAgent.toLowerCase();
if(ua.match(/opr\/([\d\.]+)/)) {
    var result = ua.match(/opr\/([\d\.]+)/);
    engine.ver = result[1];
    engine.opera = parseFloat(engine.ver);
}

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　　现在我们来打印下console.log(engine);如下所示：

　　但是呢opera29之前的版本， Opera5+也有window.opera对象，所以我们也必须检测window.opera对象，我们可以调用version()方法可以返回一个表示浏览器版本的字符串；如下代码：

if(window.opera) {
    engine.ver = window.opera.version();
    engine.opera = parseFloat(engine.ver);
}

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　　现在我们为了兼容之前及之后的opera浏览器，我们可以综合一下；如下：

var engine = client;
var ua = navigator.userAgent.toLowerCase();
if(ua.match(/opr\/([\d\.]+)/) || window.opera) {
    var result = ua.match(/opr\/([\d\.]+)/);
    engine.ver = result[1];
    engine.opera = parseFloat(engine.ver);
    if(window.opera) {
        engine.ver = window.opera.version();
        engine.opera = parseFloat(engine.ver);
    }
}

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　　现在第二步需要检测的是引擎是WebKit，因为WebKit的用户代理字符串中包含”Gecko”和”KHTML”这两个字符串，如果检测这两个，可能会有误差，但是WebKit的用户代理字符串中的”AppleWebKit”是独一无二的，因此可以根据这个来检测；

var engine = client;
var ua = navigator.userAgent.toLowerCase();
if(/applewebkit\/(\S+)/.test(ua)) {
    engine.ver = RegExp["$1"];
    engine.webkit = parseFloat(engine.ver);
}

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　　因此综合以上的所有代码如下：

var engine = client;
var ua = navigator.userAgent.toLowerCase();
if(ua.match(/opr\/([\d\.]+)/) || window.opera) {
    var result = ua.match(/opr\/([\d\.]+)/);
    engine.ver = result[1];
    engine.opera = parseFloat(engine.ver);
    if(window.opera) {
        engine.ver = window.opera.version();
        engine.opera = parseFloat(engine.ver);
    }
}else if(/applewebkit\/(\S+)/.test(ua)) {
    engine.ver = RegExp["$1"];
    engine.webkit = parseFloat(engine.ver);
}

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　　接下来要测试的呈现引擎是KHTML，同样，KHTML的用户代理字符串中也包含”Gecko”,因此在排除KHTML之前，我们无法准确检测基于Gecko浏览器。KHTML的版本号与WebKit的版本号在用户代理字符串中的格式差不多，因此也可以使用正则表达式，此外，由于Konqueror 3.1 及更早版本中不包含KHTML 的版本，故而就要使用Konqueror 的版本来代替。下面就是相应的检测代码。

if (/KHTML\/(\S+)/.test(ua) || /Konqueror\/([^;]+)/.test(ua)){
    engine.ver = RegExp["$1"];
    engine.khtml = parseFloat(engine.ver);
}

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　　下面是所有的代码：

var engine = client;
var ua = navigator.userAgent.toLowerCase();
if(ua.match(/opr\/([\d\.]+)/) || window.opera) {
    var result = ua.match(/opr\/([\d\.]+)/);
    engine.ver = result[1];
    engine.opera = parseFloat(engine.ver);
    if(window.opera) {
        engine.ver = window.opera.version();
        engine.opera = parseFloat(engine.ver);
    }
}else if(/applewebkit\/(\S+)/.test(ua)) {
    engine.ver = RegExp["$1"];
    engine.webkit = parseFloat(engine.ver);
}else if (/khtml\/(\S+)/.test(ua) || /konqueror\/([^;]+)/.test(ua)){
    engine.ver = RegExp["$1"];
    engine.khtml = parseFloat(engine.ver);
}

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　　在排除WebKit和KHTML后，就可以准确检测Gecko了，但是在用户代理字符串中，Gecko的版本号不会出现在字符串”Gecko”的后面，而是会出现在字符串”rv:”的后面。因此必须使用一个更复杂的正则表达式；

　　比如 firefox下的用户代理如下：

　　Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) Gecko/20100101 Firefox/38.0

　　如下JS代码检测：

var engine = client;
var ua = navigator.userAgent.toLowerCase();
if(/rv:([^\)]+)\) gecko\/\d{8}/.test(ua)){
    engine.ver = RegExp["$1"];
    engine.gecko = parseFloat(engine.ver);
}

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　　所以所有的JS代码如下：

var engine = client;
var ua = navigator.userAgent.toLowerCase();
if(ua.match(/opr\/([\d\.]+)/) || window.opera) {
    var result = ua.match(/opr\/([\d\.]+)/);
    engine.ver = result[1];
    engine.opera = parseFloat(engine.ver);
    if(window.opera) {
        engine.ver = window.opera.version();
        engine.opera = parseFloat(engine.ver);
    }
}else if(/applewebkit\/(\S+)/.test(ua)) {
    engine.ver = RegExp["$1"];
    engine.webkit = parseFloat(engine.ver);
}else if (/khtml\/(\S+)/.test(ua) || /konqueror\/([^;]+)/.test(ua)){
    engine.ver = RegExp["$1"];
    engine.khtml = parseFloat(engine.ver);
}else if(/rv:([^\)]+)\) gecko\/\d{8}/.test(ua)){
    engine.ver = RegExp["$1"];
    engine.gecko = parseFloat(engine.ver);
}

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　　最后一个检测就是IE浏览器了，IE的版本号位于字符串”msie”的后面，一个分号的前面；如下：

　　mozilla/5.0 (compatible; msie 9.0; windows nt 6.1; wow64; trident/7.0; slcc2; .net clr 2.0.50727; .net clr 3.5.30729; .net clr 3.0.30729; media center pc 6.0; infopath.3; .net4.0c; .net4.0e)

　　如下JS代码检测：

if (/msie ([^;]+)/.test(ua)){
    engine.ver = RegExp["$1"];
    engine.ie = parseFloat(engine.ver);
}

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　　如上；所有的代码如下：

var client = function(){
    var engine = {
        // 呈现引擎
        ie: 0,
        gecko:0,
        webkit: 0,
        khtml:0,
        opera:0,
        //其他版本号
        ver: null
    };
    // 在此检测呈现引擎，平台和设备
    return {
        engine: engine
    };
}();
var engine = client;
var ua = navigator.userAgent.toLowerCase();
if(ua.match(/opr\/([\d\.]+)/) || window.opera) {
    var result = ua.match(/opr\/([\d\.]+)/);
    engine.ver = result[1];
    engine.opera = parseFloat(engine.ver);
    if(window.opera) {
        engine.ver = window.opera.version();
        engine.opera = parseFloat(engine.ver);
    }
}else if(/applewebkit\/(\S+)/.test(ua)) {
    engine.ver = RegExp["$1"];
    engine.webkit = parseFloat(engine.ver);
}else if (/khtml\/(\S+)/.test(ua) || /konqueror\/([^;]+)/.test(ua)){
    engine.ver = RegExp["$1"];
    engine.khtml = parseFloat(engine.ver);
}else if(/rv:([^\)]+)\) gecko\/\d{8}/.test(ua)){
    engine.ver = RegExp["$1"];
    engine.gecko = parseFloat(engine.ver);
}else if (/msie ([^;]+)/.test(ua)){
    engine.ver = RegExp["$1"];
    engine.ie = parseFloat(engine.ver);
}

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　　识别浏览器

　　大多数情况下，如上面识别了引擎还不能满足我们的需求，比如苹果公司的safari浏览器和谷歌的chrome浏览器都使用了webkit作为呈现引擎；但他们的javascript引擎且不一样，在这两个浏览器中，client.webkit都会返回非0值，无法区别，因此我们还需要识别下浏览器；

　　如下增加代码如下：

var client = function(){
    var engine = {
           // 呈现引擎
           ie: 0,
           gecko:0,
           webkit: 0,
           khtml:0,
           opera:0,
           //其他版本号
           ver: null
        };
    var browser = {
            // 浏览器
            ie: 0,
            firefox:0,
            safari:0,
            konq:0,
            opera:0,
            chrome:0,
            // 其他的版本
            ver: null
        };
        // 在此检测呈现引擎，平台和设备
        return {
            engine: engine,
            browser: browser
        };
}();

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　　如上代码增加了私有变量browser,用于保存每个主要浏览器的属性，与engine变量一样，除了当前使用的浏览器，其他属性值将保持为0；如果是当前使用的浏览器，则这个属性中保存的是浮点数值形式的版本号，同样browser中的ver属性中在必要时将包含字符串形式的浏览器完整版本号；

　　因此封装后的所有JS代码如下：

var client = function(){
    var engine = {
        // 呈现引擎
        ie: 0,
        gecko:0,
        webkit: 0,
        khtml:0,
        opera:0,
        //其他版本号
        ver: null
    };
    var browser = {
        // 浏览器
        ie: 0,
        firefox:0,
        safari:0,
        konq:0,
        opera:0,
        chrome:0,
        // 其他的版本
        ver: null
    };
    // 在此检测呈现引擎，平台和设备
    return {
        engine: engine,
        browser: browser
    };
}();
var engine = client;
var browser = client;
var ua = navigator.userAgent.toLowerCase();
if(ua.match(/opr\/([\d\.]+)/) || window.opera) {
    var result = ua.match(/opr\/([\d\.]+)/);
    engine.ver = browser.ver = result[1];
    engine.opera = browser.opera = parseFloat(engine.ver);
    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
    /*
     * chrome用户代理字符串
     * Mozilla/5.0 (Windows NT 6.1; WOW64)        AppleWebKit/537.36 (KHTML, like Gecko) 
     * Chrome/42.0.2311.152 Safari/537.36
     */
    if(/chrome\/(\S+)/.test(ua)) {
        browser.ver = RegExp["$1"];
        browser.chrome = parseFloat(browser.ver);
    }else if(/version\/(\S+)/.test(ua)) {
        /*
         * safari用户代理字符串
         * Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/534.57.2 (KHTML, like Gecko) 
         * Version/5.1.7 Safari/534.57.2
         */
        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);
        /*
         * firefox的用户代理的字符串
         * Mozilla/5.0 (Windows NT 6.1; WOW64; rv:38.0) 
         * Gecko/20100101 Firefox/38.0
         */
        // 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) || "ActiveXObject" in window){
    if("ActiveXObject" in window) {
        if(/msie ([^;]+)/.test(ua)) {
            engine.ver = browser.ver = RegExp["1"];            
             engine.ie = browser.ie = parseFloat(engine.ver);         
             }else {             
             // ie11+             
             if(/rv:([^\)]+)\)/.test(ua)) {                 
             engine.ver = browser.ver = RegExp["1"];             
             engine.ie = browser.ie = parseFloat(engine.ver);         
             }else {             
             // ie11+             
             if(/rv:([^\)]+)\)/.test(ua)) {                 
             engine.ver = browser.ver = RegExp["1"];
                engine.ie = browser.ie = parseFloat(engine.ver);
            }
        }
    }
		 }
// 可以打印下
console.log(browser);

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　　对opera和IE而言，browser对象中的值等于engine对象中值，对Konqueror 而言，browser.

　　konq 和browser.ver 属性分别等于engine.khtml 和engine.ver 属性。为了检测Chrome 和Safari，我们在检测引擎的代码中添加了if 语句。提取Chrome 的版本号时，需要查找字符串"chrome/"并取得该字符串后面的数值。而提取Safari 的版本号时，则需要查找字符串"version/"并取得其后的数值。由于这种方式仅适用于Safari 3 及更高版本，因此需要一些备用的代码，将WebKit 的版本号近似地映射为Safari 的版本号(至于else后面的就不多讲)。在检测Firefox 的版本时，首先要找到字符串"firefox/"，然后提取出该字符串后面的数值。

　　有了上面的代码，我们就可以编写下面的代码判断了，如下代码：

if (client.engine.webkit) { 
    //if it’s WebKit
    if (client.browser.chrome){
       //执行针对Chrome 的代码
    } else if (client.browser.safari){
       //执行针对Safari 的代码
    }
} else if (client.engine.gecko){
    if (client.browser.firefox){
        //执行针对Firefox 的代码
    } else {
       //执行针对其他Gecko 浏览器的代码
    }
}

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　　识别平台

　　目前有三大主流平台(windows,Mac,Unix(包括各种linux))；因为那些浏览器(safari,opera,firefox)在不同的平台可能会有不同的问题；为了检测这些平台，还需要像下面这样再添加一个新对象；

var client = function(){
    var engine = {
        // 呈现引擎
        ie: 0,
        gecko:0,
        webkit: 0,
        khtml:0,
        opera:0,
        //其他版本号
        ver: null
    };
    var browser = {
        // 浏览器
        ie: 0,
        firefox:0,
        safari:0,
        konq:0,
        opera:0,
        chrome:0,
         // 其他的版本
          ver: null
     };
    var system = {
        win: false,
        mac: false,
        xll: false
    };
    // 在此检测呈现引擎，平台和设备
    return {
        engine: engine,
        browser: browser,
        system: system
    };
}();

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　　如上的代码添加了一个包含3个属性的新变量system，其中，win属性表示是否为windows平台，mac代表Mac，xll代表是Unix，system的对象的属性默认都为false，在确定平台时，检测navigator.platform要比检测用户代理字符串更简单，检测用户代理字符串在不同的浏览器中会给出不同的平台信息，而navigator.platform属性可能的值包括”Win32”,”Win64”,”MacPPC”,”MacIntel”,”Xll”和”Linux i686”,这些值在不同的浏览器中都是一致的，检测代码非常直观；如下代码：

var system = client;
var platform = navigator.platform;
system.win = platform.indexOf("Win") == 0;
system.mac = platform.indexOf("Mac") == 0;
system.x11 = (platform.indexOf("X11") == 0) || (platform.indexOf("Linux") == 0);

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　　比如我现在在chrome浏览器下打印如下：

　　console.log(system)

　　截图如下：

　　如果我想知道是win32或者是win64的话，我们可以使用这句代码打印即可

　　Console.log(navigator.platform);

　　识别移动设备

　　可以通过简单地检测字符串”iPhone”,”iPod”,”iPad”,就可以分别设置响应属性的值了。

system.iphone = ua.indexOf(“iphone”) > -1;
system.ipod = ua.indexOf(“ipod”) > -1;
system.ipad = ua.indexOf(“ipad”) > -1;

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