js

<script type="text/javascript">

    is_mobile();
    function is_mobile() {
        var ua = navigator.userAgent;

        var url = window.location.host;

        var ipad = ua.match(/(iPad).*OS\s([\d_]+)/),

            isIphone =!ipad && ua.match(/(iPhone\sOS)\s([\d_]+)/),

            isAndroid = ua.match(/(Android)\s+([\d.]+)/),

            isMobile = isIphone || isAndroid;

        //判断

        if(! isMobile){
            window.location.href = "";
        }
    }
</script>

PHP

一

/**
 * 判断当前访问的用户是 PC端 还是 手机端 返回true 为手机端 false 为PC 端
 * @return boolean
 */
function isMobile(){ 
  $useragent=isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : ''; 
  //echo $useragent;die;
  $useragent_commentsblock=preg_match('|\(.*?\)|',$useragent,$matches)>0?$matches[0]:'';    
  function CheckSubstrs($substrs,$text){ 
    foreach($substrs as $substr) 
      if(false!==strpos($text,$substr)){ 
        return true; 
      } 
      return false; 
  }
  $mobile_os_list=array('Google Wireless Transcoder','Windows CE','WindowsCE','Symbian','Android','armv6l','armv5','Mobile','CentOS','mowser','AvantGo','Opera Mobi','J2ME/MIDP','Smartphone','Go.Web','Palm','iPAQ');
  $mobile_token_list=array('Profile/MIDP','Configuration/CLDC-','160×160','176×220','240×240','240×320','320×240','UP.Browser','UP.Link','SymbianOS','PalmOS','PocketPC','SonyEricsson','Nokia','BlackBerry','Vodafone','BenQ','Novarra-Vision','Iris','NetFront','HTC_','Xda_','SAMSUNG-SGH','Wapaka','DoCoMo','iPhone','iPod'); 
 
  $found_mobile=CheckSubstrs($mobile_os_list,$useragent_commentsblock) || 
       CheckSubstrs($mobile_token_list,$useragent); 
 
  if ($found_mobile){ 
    return true; 
  }else{ 
    return false; 
  } 
}

二

function is_mobile()
{
        $agent = strtolower($_SERVER['HTTP_USER_AGENT']);
        $is_pc = (strpos($agent, 'windows nt')) ? true : false;
        $is_mac = (strpos($agent, 'mac os')) ? true : false;
        $is_iphone = (strpos($agent, 'iphone')) ? true : false;
        $is_android = (strpos($agent, 'android')) ? true : false;
        $is_ipad = (strpos($agent, 'ipad')) ? true : false;
        
        if($is_iphone){
              return  true;
        }
        if($is_android){
              return  true;
        }
        if($is_ipad){
              return  true;
        }
        if($is_pc){
              return  false;
        } 
        if($is_mac){
              return  false;
        }
}

三

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

判断微信

    function isWeixin() {
        if (strpos($_SERVER['HTTP_USER_AGENT'], 'MicroMessenger') !== false) {
            return true;
        } else {
            return false;
        }
    }