PHP gets the current domain name, host, URL, port, parameters, URL, path, proxy, etc.

  //Get the domain name or host address
 echo $_SERVER['HTTP_HOST']."";
 //Get the web page address
 echo $_SERVER['PHP_SELF'] ."";
 //Get URL parameters
 echo $_SERVER["QUERY_STRING"]."";
 //Get user agent
 echo $_SERVER['HTTP_REFERER'] ."";
 //Get the complete url
 echo 'http://'.$_SERVER['HTTP_HOST'].$_SERVER['REQUEST_URI'];
 echo 'http://' .$_SERVER['HTTP_HOST'].$_SERVER['PHP_SELF'].'?'.$_SERVER['QUERY_STRING'];
 //Full url including port number
 echo 'http://'.$_SERVER[ 'SERVER_NAME'].':'.$_SERVER["SERVER_PORT"].$_SERVER["REQUEST_URI"];
 //Only get the path
 $url='http://'.$_SERVER['SERVER_NAME']. $_SERVER["REQUEST_URI"];
 echo dirname($url);
 ?>

php, URL