Question

我尝试检测浏览器版本，以便检测当前浏览器是Internet Explorer版本优于8还是egual。然而，它似乎不起作用，我有这个错误（在Firefox中，有时在谷歌浏览器中）：

Undefined index: HTTP_USER_AGENT in

这是我的代码：

 preg_match('/MSIE (.*?);/', $_SERVER['HTTP_USER_AGENT'], $matches);
 if(count($matches)<2){
    preg_match('/Trident\/\d{1,2}.\d{1,2}; rv:([0-9]*)/', $_SERVER['HTTP_USER_AGENT'], $matches);
 }
 if (count($matches)>1){
    $version = $matches[1];
 } else {
    $version = 999;
 }

 if($version >= 9) {
    wp_enqueue_script('preloader');
 }

Answer 1

Undefined index: HTTP_USER_AGENT

此错误消息表明您正在处理的请求根本不包含User-Agent标头，因此HTTP_USER_AGENT中不存在$_SERVER密钥。没有办法弄清楚PHP涉及哪些浏览器，因为浏览器还没有识别出来。（它很可能根本不是网络浏览器。）

Answer 2

没有get_browser替代品输出我使用Opera或Chrome查找的正确名称/版本组合。他们要么提供错误的名称，例如Safari，实际上它应该是Chrome，如果ua字符串包含与最新版Chrome和Opera相同的版本号，则会报告错误的数字。这是一个可以检查版本的函数。

<?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 seperately 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);
?>

php检测浏览器版本HTTP_USER_AGENT

2 个答案: