php判断手机移动设备访问

<?php
function isMobile()
{ 
    // 如果有HTTP_X_WAP_PROFILE则一定是移动设备
    if (isset ($_SERVER[&#39;HTTP_X_WAP_PROFILE&#39;]))
    {
        return true;
    } 
    // 如果via信息含有wap则一定是移动设备,部分服务商会屏蔽该信息
    if (isset ($_SERVER[&#39;HTTP_VIA&#39;]))
    { 
        // 找不到为flase,否则为true
        return stristr($_SERVER[&#39;HTTP_VIA&#39;], "wap") ? true : false;
    } 
    // 脑残法，判断手机发送的客户端标志,兼容性有待提高
    if (isset ($_SERVER[&#39;HTTP_USER_AGENT&#39;]))
    {
        $clientkeywords = array (&#39;nokia&#39;,
            &#39;sony&#39;,
            &#39;ericsson&#39;,
            &#39;mot&#39;,
            &#39;samsung&#39;,
            &#39;htc&#39;,
            &#39;sgh&#39;,
            &#39;lg&#39;,
            &#39;sharp&#39;,
            &#39;sie-&#39;,
            &#39;philips&#39;,
            &#39;panasonic&#39;,
            &#39;alcatel&#39;,
            &#39;lenovo&#39;,
            &#39;iphone&#39;,
            &#39;ipod&#39;,
            &#39;blackberry&#39;,
            &#39;meizu&#39;,
            &#39;android&#39;,
            &#39;netfront&#39;,
            &#39;symbian&#39;,
            &#39;ucweb&#39;,
            &#39;windowsce&#39;,
            &#39;palm&#39;,
            &#39;operamini&#39;,
            &#39;operamobi&#39;,
            &#39;openwave&#39;,
            &#39;nexusone&#39;,
            &#39;cldc&#39;,
            &#39;midp&#39;,
            &#39;wap&#39;,
            &#39;mobile&#39;
            ); 
        // 从HTTP_USER_AGENT中查找手机浏览器的关键字
        if (preg_match("/(" . implode(&#39;|&#39;, $clientkeywords) . ")/i", strtolower($_SERVER[&#39;HTTP_USER_AGENT&#39;])))
        {
            return true;
        } 
    } 
    // 协议法，因为有可能不准确，放到最后判断
    if (isset ($_SERVER[&#39;HTTP_ACCEPT&#39;]))
    { 
        // 如果只支持wml并且不支持html那一定是移动设备
        // 如果支持wml和html但是wml在html之前则是移动设备
        if ((strpos($_SERVER[&#39;HTTP_ACCEPT&#39;], &#39;vnd.wap.wml&#39;) !== false) && (strpos($_SERVER[&#39;HTTP_ACCEPT&#39;], &#39;text/html&#39;) === false || (strpos($_SERVER[&#39;HTTP_ACCEPT&#39;], &#39;vnd.wap.wml&#39;) < strpos($_SERVER[&#39;HTTP_ACCEPT&#39;], &#39;text/html&#39;))))
        {
            return true;
        } 
    } 
    return false;
} 
?>