php针对服务器端预定义变量调用及字符串处理的方法

<?php
$ADMIN = array(
  &#39;defaulturl&#39;=> &#39;http://blog.qita.in/images/banner-header.gif&#39;,
  //盗链返回的地址
  &#39;url_1&#39;   => &#39;http://blog.qita.in/file&#39;,
  &#39;url_2&#39;   => &#39;http://blog.qita.in/file1&#39;,
);
$okaysites = array(
 &#39;http://qita.in&#39;,
  &#39;http://blog.qita.in&#39;, //白名单
  &#39;http://blog.qita.in/1.html&#39;,
);
$reffer = $_SERVER[&#39;HTTP_REFERER&#39;];
if ($reffer) {
  $yes = 0;
  while (list($domain, $subarray) = each($okaysites)) {
    if (ereg($subarray, "$reffer")) {
      $yes = 1;
    }
  }
  $theu = &#39;url_&#39; . $_GET[&#39;site&#39;];
  $file = $_GET[&#39;file&#39;];
  if ($ADMIN[$theu] and $yes == 1) {
  header("Location: $ADMIN[$theu]/$file");
  } else {
    header("Location: $ADMIN[defaulturl]");
  }
} else {
  header("Location: $ADMIN[defaulturl]");
}
print_r($_SERVER[&#39;HTTP_REFERER&#39;]);
?>