从 Opera 浏览器测试时，UserAgent 中包含的所有浏览器名称

Question

我的用户代理在 Opera 浏览器中测试时显示：

Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.125 Safari/537.36 OPR/30.0.1835.88

现在，我有以下脚本来测试浏览器：

$browser_list = array(
            array('search_string' => 'chrome', 'bname' => 'Google Chrome', 'matchname' => 'chrome', 'ub' => 'Chrome'),
            array('search_string' => 'firefox', 'bname' => 'Mozilla Firefox', 'matchname' => 'firefox', 'ub' => 'Firefox'),
            array('search_string' => 'safari', 'bname' => 'Apple Safari', 'matchname' => 'Safari', 'ub' => 'Safari'),
            array('search_string' => 'netscape', 'bname' => 'Netscape', 'matchname' => 'Netscape', 'ub' => 'Netscape'),
            array('search_string' => 'opera', 'bname' => 'Opera', 'matchname' => 'Opera', 'ub' => 'Opera'), // Must be before IE
            array('search_string' => 'MSIE', 'bname' => 'Internet Explorer', 'matchname' => 'IE', 'ub' => 'MSIE'),
            array('search_string' => 'Mozilla', 'bname' => 'Internet Explorer', 'matchname' => 'IE', 'ub' => 'MSIE'), // Hack for IE 11 as the LAST one so you know not match the above
        );

    // Next get the name of the useragent yes seperately and for good reason
    foreach ($browser_list as $item) {
    echo $item['search_string'];
        if (stripos($userAgent, $item['search_string']) !== false) {
            $bname = $item['bname'];
            $matchname = $item['matchname'];
            $ub = $item['ub'];
            echo "breaking";
            break;
        }
    }

但是，由于 UserAgent 包含所有浏览器名称，所以我遇到了问题。

另外，为什么 Opera 的 usergent 这么奇怪？

Answer 1

Mozilla/5.0 (Windows NT 5.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/43.0.2357.125 Safari/537.36 OPR/30.0.1835.88

您必须首先在用户代理中搜索“OPR/”字符串。 这就是 Opera 与其他浏览器的不同之处。

如果找到此字符串，请停止搜索。其他，继续。所以不会和其他浏览器混淆。

Answer 2

新的浏览器通常很擅长跟上新的标准，甚至微软的“Edge”浏览器也跟得上速度。

因此，除 Firefox 之外的所有浏览器制造商都在用户代理字符串中包含“Chrome”和“Safari”，以确保执行浏览器嗅探以降低其他浏览器功能的网站显示完整功能。请参阅this answer to a related question，其中有更多详细信息。

See this for a detailed walkthrough on browser detection

通常，您应该避免浏览器检测，而是尽可能使用功能检测，但这必须在需要特殊功能的客户端完成。

---

特别是关于Opera标签，当他们使用他们自己的“Presto”引擎时，直到版本12被识别为“Opera”，但在那之后，他们开始使用基于“Blink”的引擎，所以他们不得不开始使用不同的标签来区分旧的 Opera 引擎。

事实上，仍有相当多的用户仍在使用 Opera 12，这主要不是因为 HTML 引擎，而是因为额外的高级功能，比如内置的电子邮件客户端。

---

在我拥有的一个测试站点中，我使用这个 javascript 代码来嗅探用户代理并提取浏览器和版本信息以显示在页面上。我将其包括在内以可视化用户代理嗅探的真正复杂程度。 此代码还支持您可能不知道的浏览器，如果它们遵循模式将其唯一的浏览器/版本作为列表中的最后一个（这似乎是最新浏览器的常见模式 - 除了 Chrome）。

    var browserName  = navigator.appName;
    var fullVersion  = ''+parseFloat(navigator.appVersion); 
    var majorVersion = parseInt(navigator.appVersion,10);
    var nVer = navigator.appVersion;
    var nAgt = navigator.userAgent;
    var nameOffset,verOffset,ix;

    // In Opera (Presto, up to version 12), the true version is after "Opera" or after "Version"
    if ((verOffset=nAgt.indexOf("Opera"))!=-1) {
     browserName = "Opera";
     fullVersion = nAgt.substring(verOffset+6);
     if ((verOffset=nAgt.indexOf("Version"))!=-1) 
       fullVersion = nAgt.substring(verOffset+8);
    }
    // In MSIE, the true version is after "MSIE" in userAgent
    else if ((verOffset=nAgt.indexOf("MSIE"))!=-1) {
     browserName = "Microsoft Internet Explorer";
     fullVersion = nAgt.substring(verOffset+5);
    }
    // In MSIE 11, the string "MSIE" is not longer present in userAgent
    // Check for the engine "Trident" instead
    else if ((verOffset=nAgt.indexOf("Trident"))!=-1) {
     browserName = "Microsoft Internet Explorer";
     verOffset = nAgt.indexOf("rv:");
     fullVersion = nAgt.substring(verOffset+3);
    }

    // In Safari, the true version is after "Safari" or after "Version"
    // Nowdays, most browsers include "Safari", so you also need to make sure it does NOT contain "Chrom" (as they also include "Crome", but Safari don't.
    else if ((verOffset=nAgt.indexOf("Safari"))!=-1 && nAgt.indexOf("Chrom")<0) {
     browserName = "Safari";
     fullVersion = nAgt.substring(verOffset+7);
     if ((verOffset=nAgt.indexOf("Version"))!=-1) 
       fullVersion = nAgt.substring(verOffset+8);
    }
    // In most other browsers, "name/version" is at the end of userAgent 
    else if ( (nameOffset=nAgt.lastIndexOf(' ')+1) < 
              (verOffset=nAgt.lastIndexOf('/')) ) 
    {
     browserName = nAgt.substring(nameOffset,verOffset);
     if (browserName==="Safari") {
      // Safari is last when browser is Chrome. 
      // Safari is handled already, so this has to be Chrome!
      verOffset=nAgt.indexOf("Chrome") + 6;
      browserName = "Chrome";
     }
     fullVersion = nAgt.substring(verOffset+1);
     if (browserName.toLowerCase()==browserName.toUpperCase()) {
      browserName = navigator.appName;
     }
    }
    // trim the fullVersion string at semicolon/space if present
    if ((ix=fullVersion.indexOf(";"))!=-1)
       fullVersion=fullVersion.substring(0,ix);
    if ((ix=fullVersion.indexOf(" "))!=-1)
       fullVersion=fullVersion.substring(0,ix);

    majorVersion = parseInt(''+fullVersion,10);
    if (isNaN(majorVersion)) {
       fullVersion  = ''+parseFloat(navigator.appVersion); 
       majorVersion = parseInt(navigator.appVersion,10);
    }

    var engine = null;
    
    if (window.navigator.appName == "Microsoft Internet Explorer")
    {
      // This is an IE browser. What mode is the engine in?
      if (document.documentMode) // IE8 or later
        engine = document.documentMode;
      else // IE 5-7
      {
        engine = 5; // Assume quirks mode unless proven otherwise
        if (document.compatMode)
        {
          if (document.compatMode == "CSS1Compat")
            engine = 7; // standards mode
        }
        // There is no test for IE6 standards mode because that mode  
        // was replaced by IE7 standards mode; there is no emulation.
      }
      // the engine variable now contains the document compatibility mode.
    }

    var browserDetailsContent = ''
     +'<li><b>Browser name:              </b>' + browserName+'</li>'
     +'<li><b>Full version:              </b>' + fullVersion+'</li>'
     +'<li><b>Major version:             </b>' + majorVersion+'</li>'
     +'<li><b>navigator.appVersion:      </b>' + navigator.appVersion+'</li>'
     +'<li><b>navigator.appMinorVersion: </b>' + navigator.appMinorVersion+'</li>'
     +'<li><b>navigator.appCodeName:     </b>' + navigator.appCodeName+'</li>'
     +'<li><b>navigator.appName:         </b>' + navigator.appName+'</li>'
     +'<li><b>navigator.userAgent:       </b>' + navigator.userAgent+'</li>'
     +'<li><b>Internet Explorer engine:  </b>' + engine+'</li>'
    ;
    document.write(browserDetailsContent);