我发现在 JS 中执行此操作的最佳方法是使用Quirksmode。我为 PHP 制作了一个，它应该可以与普通浏览器一起使用：

  $browser = array(
    'version'   => '0.0.0',
    'majorver'  => 0,
    'minorver'  => 0,
    'build'     => 0,
    'name'      => 'unknown',
    'useragent' => ''
  );

  $browsers = array(
    'firefox', 'msie', 'opera', 'chrome', 'safari', 'mozilla', 'seamonkey', 'konqueror', 'netscape',
    'gecko', 'navigator', 'mosaic', 'lynx', 'amaya', 'omniweb', 'avant', 'camino', 'flock', 'aol'
  );

  if (isset($_SERVER['HTTP_USER_AGENT'])) {
    $browser['useragent'] = $_SERVER['HTTP_USER_AGENT'];
    $user_agent = strtolower($browser['useragent']);
    foreach($browsers as $_browser) {
      if (preg_match("/($_browser)[\/ ]?([0-9.]*)/", $user_agent, $match)) {
        $browser['name'] = $match[1];
        $browser['version'] = $match[2];
        @list($browser['majorver'], $browser['minorver'], $browser['build']) = explode('.', $browser['version']);
        break;
      }
    }
  }

这是 JavaScript 代码，您可以通过它轻松检测浏览器。

    var userAgent = navigator.userAgent.toLowerCase();

    // Figure out what browser is being used.
    var Browser = {
        Version: (userAgent.match(/.+(?:rv|it|ra|ie)[\/: ]([\d.]+)/) || [])[1],
        Chrome: /chrome/.test(userAgent),
        Safari: /webkit/.test(userAgent),
        Opera: /opera/.test(userAgent),
        IE: /msie/.test(userAgent) && !/opera/.test(userAgent),
        Mozilla: /mozilla/.test(userAgent) && !/(compatible|webkit)/.test(userAgent),
        Check: function() { alert(userAgent); }
    };

    if (Browser.Chrome || Browser.Mozilla) {
        // Do your stuff for Firefox and Chrome.
    }
    else if (Browser.IE) {
        // Do something related to Internet Explorer.
    }
    else {
        // The browser is Safari, Opera or some other.
    }

实际上，PHP 中有一个函数get_browser。

get_browser() 中的PHP 代码完全适合我；)

<?php
    function getBrowser()
    {
        $u_agent = $_SERVER['HTTP_USER_AGENT'];
        $bname = 'Unknown';
        $platform = 'Unknown';
        $version= "";

        //First get the platform?
        if (preg_match('/linux/i', $u_agent)) {
            $platform = 'linux';
        }
        elseif (preg_match('/macintosh|mac os x/i', $u_agent)) {
            $platform = 'mac';
        }
        elseif (preg_match('/windows|win32/i', $u_agent)) {
            $platform = 'windows';
        }

        // Next get the name of the useragent yes separately and for good reason.
        if (preg_match('/MSIE/i',$u_agent) && !preg_match('/Opera/i',$u_agent))
        {
            $bname = 'Internet Explorer';
            $ub = "MSIE";
        }
        elseif (preg_match('/Firefox/i',$u_agent))
        {
            $bname = 'Mozilla Firefox';
            $ub = "Firefox";
        }
        elseif (preg_match('/Chrome/i',$u_agent))
        {
            $bname = 'Google Chrome';
            $ub = "Chrome";
        }
        elseif (preg_match('/Safari/i',$u_agent))
        {
            $bname = 'Apple Safari';
            $ub = "Safari";
        }
        elseif (preg_match('/Opera/i',$u_agent))
        {
            $bname = 'Opera';
            $ub = "Opera";
        }
        elseif (preg_match('/Netscape/i',$u_agent))
        {
            $bname = 'Netscape';
            $ub = "Netscape";
        }

        // Finally get the correct version number.
        $known = array('Version', $ub, 'other');
        $pattern = '#(?<browser>' . join('|', $known) .
        ')[/ ]+(?<version>[0-9.|a-zA-Z.]*)#';
        if (!preg_match_all($pattern, $u_agent, $matches)) {
            // we have no matching number just continue
        }

        // See how many we have.
        $i = count($matches['browser']);
        if ($i != 1) {
            //we will have two since we are not using 'other' argument yet
            //see if version is before or after the name
            if (strripos($u_agent,"Version") < strripos($u_agent,$ub)){
                $version= $matches['version'][0];
            }
            else {
                $version= $matches['version'][1];
            }
        }
        else {
            $version= $matches['version'][0];
        }

        // Check if we have a number.
        if ($version==null || $version=="") {$version="?";}

        return array(
            'userAgent' => $u_agent,
            'name'      => $bname,
            'version'   => $version,
            'platform'  => $platform,
            'pattern'    => $pattern
        );
    }

    // Now try it.
    $ua=getBrowser();
    $yourbrowser= "Your browser: " . $ua['name'] . " " . $ua['version'] . " on " .
                  $ua['platform'] . " reports: <br >" . $ua['userAgent'];
    print_r($yourbrowser);
?>

1) 99.9% 准确检测器：BrowserDetection.php （示例）

2）最简单的功能（但不准确的欺骗）：

<?php
function get_user_browser()
{
    $u_agent = $_SERVER['HTTP_USER_AGENT'];        $ub = '';
    if(preg_match('/MSIE/i',$u_agent))          {   $ub = "ie";     }
    elseif(preg_match('/Firefox/i',$u_agent))   {   $ub = "firefox";    }
    elseif(preg_match('/Safari/i',$u_agent))    {   $ub = "safari"; }
    elseif(preg_match('/Chrome/i',$u_agent))    {   $ub = "chrome"; }
    elseif(preg_match('/Flock/i',$u_agent)) {   $ub = "flock";      }
    elseif(preg_match('/Opera/i',$u_agent)) {   $ub = "opera";      }
  return $ub;
}
?>