1.

function getUrl() {

  $url  = @( $_SERVER["HTTPS"] != 'on' ) ? 'http://'.$_SERVER["SERVER_NAME"] :  'https://'.$_SERVER["SERVER_NAME"];

  $url .= ( $_SERVER["SERVER_PORT"] !== 80 ) ? ":".$_SERVER["SERVER_PORT"] : "";

  $url .= $_SERVER["REQUEST_URI"];

  return $url;

} 

2. SSL 고려

function​ getUrl() {

  $url  = 'http' . ( ISSET( $_SERVER['HTTPS'] ) && 'on' === $_SERVER['HTTPS'] ) ? 's' : '';

  $url .= '://' . $_SERVER["SERVER_NAME"];

  $url .= ( IN_ARRAY( ARRAY( '80' , '443' ) , $_SERVER["SERVER_PORT"] ) ? ":" . $_SERVER['SERVER_PORT'] : '';

  $url .= $_SERVER['REQUEST_URI'];

  RETURN $url;

} 

3. 

function getCurrentUrl() {

        $url  = isset( $_SERVER['HTTPS'] ) && 'on' === $_SERVER['HTTPS'] ? 'https' : 'http';

        $url .= '://' . $_SERVER['SERVER_NAME'];

        $url .= in_array( $_SERVER['SERVER_PORT'], array('80', '443') ) ? '' : ':' . $_SERVER['SERVER_PORT'];

        $url .= $_SERVER['REQUEST_URI'];

        return $url;

    }