PHP 获取用户访问的来源链路或直接访问 HTTP_REFERER

标准式代码

<?php
$REFERER = $_SERVER['HTTP_REFERER'];
if(empty($REFERER)) echo "Direct";
else echo $_SERVER['HTTP_REFERER'];
?>

简洁行代码

<?php if(empty($_SERVER['HTTP_REFERER'])) echo "Direct"; else echo $_SERVER['HTTP_REFERER']; ?>