title: Customize upload folder for sites
body: <p>I´ve just installed a wordpress multisite installation (version 4.2.1) with mapped domains.</p>
  
  <p>For each site the url for an uploaded image which is shown in the browser is <code>http://URL/wp-content/uploads/sites/SITENUMBER/DATE/...</code> and the folder is <code>/path/to/wordpress/wp-content/uploads/sites/SITENUMBER/DATE/...</code>.
  But I want to use the local path <code>/path/to/wordpress/wp-content/uploads/sites/SITENUMBER/...</code> and want to see in the browser <code>http://URL/wp-content/uploads/DATE/...</code> (like in a single wordpress site).</p>
  
  <p>I´ve read a much about that and I think I know that the option "UPLOAD URL PATH" normally should rewrite this, doesn´t it? But for me it doesn´t work. How could I customize wordpress to fit it?</p>
  
  <p>Update: I´ve found out that in functions.php are define that multisites will get a rewrite of the URL:</p>
  
  <pre><code>// If multisite (and if not the main site in a post-MU network)
  if ( is_multisite() &amp;&amp; ! ( is_main_network() &amp;&amp; is_main_site() &amp;&amp; defined( 'MULTISITE' ) ) ) {
  
  if ( ! get_site_option( 'ms_files_rewriting' ) ) {
  /*
  * If ms-files rewriting is disabled (networks created post-3.5), it is fairly
  * straightforward: Append sites/%d if we're not on the main site (for post-MU
  * networks). (The extra directory prevents a four-digit ID from conflicting with
  * a year-based directory for the main site. But if a MU-era network has disabled
  * ms-files rewriting manually, they don't need the extra directory, as they never
  * had wp-content/uploads for the main site.)
  */
  
      if ( defined( 'MULTISITE' ) )
          $ms_dir = '/sites/' . get_current_blog_id();
      else
          $ms_dir = '/' . get_current_blog_id();
  
      $dir .= $ms_dir;
      $url .= $ms_dir;
      ...
  }}
  </code></pre>
  
  <p>But I didn´t know how I could change this to get the needed behavior.</p>