域名跳转：QQ/微信内访问检测及随机分配

$j46 = $conf['j46'];
$j47 = $conf['j47'];

if ($j47 == 1) {
  $domains = explode(',', '$j46');
  $chosen_domain = $domains[array_rand($domains)]; // 随机获取$j46里的一个值

  if (!isset($_COOKIE['redirected'])) {
    setcookie('redirected', 'true', time() + 10);
    $current_url = 'http://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
    $new_url = 'http://' . $chosen_domain . $_SERVER['REQUEST_URI'];
    header('Refresh: 2; URL=' . $new_url);
    echo '<title>跳转中，请稍等 </title>
    <style>
      * {margin: 0; padding: 0; font-family: 'Microsoft YaHei'; color: #fff;}
      body, div, form, input, li, ol, p, textarea, ul {margin: 0; padding: 0; font-family: 'Microsoft YaHei'; color: #fff;}
      body {background: #fff; color: #3f3f3f; font-family: Apple LiGothic Medium, SimHei, Geneva, Arial, Helvetica, sans-serif; -webkit-tap-highlight-color: transparent; -webkit-tap-highlight-color: transparent; -webkit-touch-callout: none; -webkit-appearance: none; width: 100%; font-size: 12px;}
      body p {color: white; text-align: center; line-height: 25px;}
      .spinner {margin: 100px auto; width: 40px; height: 20px; position: relative;}
      .container1 > div, .container2 > div, .container3 > div {width: 6px; height: 6px; background-color: #333; border-radius: 100%; position: absolute; -webkit-animation: bouncedelay 1.2s infinite ease-in-out; animation: bouncedelay 1.2s infinite ease-in-out; -webkit-animation-fill-mode: both; animation-fill-mode: both;}
      .spinner .spinner-container {position: absolute; width: 100%; height: 100%;}
      .container2 {-webkit-transform: rotateZ(45deg); transform: rotateZ(45deg);}
      .container3 {-webkit-transform: rotateZ(90deg); transform: rotateZ(90deg);}
      .circle1 {top: 0; left: 0;}
      .circle2 {top: 0; right: 0;}
      .circle3 {right: 0; bottom: 0;}
      .circle4 {left: 0; bottom: 0;}
      .container2 .circle1 {-webkit-animation-delay: -1.1s; animation-delay: -1.1s;}
      .container3 .circle1 {-webkit-animation-delay: -1.0s; animation-delay: -1.0s;}
      .container1 .circle2 {-webkit-animation-delay: -0.9s; animation-delay: -0.9s;}
      .container2 .circle2 {-webkit-animation-delay: -0.8s; animation-delay: -0.8s;}
      .container3 .circle2 {-webkit-animation-delay: -0.7s; animation-delay: -0.7s;}
      .container1 .circle3 {-webkit-animation-delay: -0.6s; animation-delay: -0.6s;}
      .container2 .circle3 {-webkit-animation-delay: -0.5s; animation-delay: -0.5s;}
      .container3 .circle3 {-webkit-animation-delay: -0.4s; animation-delay: -0.4s;}
      .container1 .circle4 {-webkit-animation-delay: -0.3s; animation-delay: -0.3s;}
      .container2 .circle4 {-webkit-animation-delay: -0.2s; animation-delay: -0.2s;}
      .container3 .circle4 {-webkit-animation-delay: -0.1s; animation-delay: -0.1s;}
      @-webkit-keyframes bouncedelay {0%, 80%, 100% {-webkit-transform: scale(0.0)} 40% {-webkit-transform: scale(1.0)}}
      @keyframes bouncedelay {0%, 80%, 100% {transform: scale(0.0); -webkit-transform: scale(0.0);} 40% {transform: scale(1.0); -webkit-transform: scale(1.0);}}
    </style>

    <div id='paneloading' style='display:'>
      <div class='spinner'>
        <div class='spinner-container container1'>
          <div class='circle1'></div>
          <div class='circle2'></div>
          <div class='circle3'></div>
          <div class='circle4'></div>
        </div>
        <div class='spinner-container container2'>
          <div class='circle1'></div>
          <div class='circle2'></div>
          <div class='circle3'></div>
          <div class='circle4'></div>
        </div>
        <div class='spinner-container container3'>
          <div class='circle1'></div>
          <div class='circle2'></div>
          <div class='circle3'></div>
          <div class='circle4'></div>
        </div>
      </div>
    </div>';

  // 判断是否可以在QQ和微信内访问
  if (strpos($_SERVER['HTTP_USER_AGENT'], 'QQ/') !== false || strpos($_SERVER['HTTP_USER_AGENT'], 'MicroMessenger') !== false) {
    $can_access = false;
    foreach ($domains as $domain) {
      $headers = get_headers('http://$domain');
      if (strpos($headers[0], '200') !== false) {
        $can_access = true;
        break;
      }
    }
    if ($can_access) {
      // 可以访问，跳转
      header('Refresh: 2; URL=' . $new_url);
      echo '<title>跳转中，请稍等 </title>
      // 省略loading动画代码
      ';
    } else {
      // 无可用域名
      echo '无可用域名';
    }
  } else {
    // 不在QQ和微信内，直接跳转
    header('Refresh: 2; URL=' . $new_url);
    echo '<title>跳转中，请稍等 </title>
    // 省略loading动画代码
    ';
  }
}