attachment rewrite

gistfile1.aw

add_filter( 'generate_rewrite_rules', 'press_attachment_rewrite' );
add_filter( 'template_redirect', 'press_redirect_old_attachment' );
/* add new rewrite rule */
	function attachment_rewrite( $wp_rewrite ) {
	    $rule = array(
	        'media/(.+)' => 'index.php?attachment=' . $wp_rewrite->preg_index(1)
	    );
	
	    $wp_rewrite->rules = $rule + $wp_rewrite->rules;
	}


/* redirect standard wordpress attachments urls to new format */
	function redirect_old_attachment() {
	    global $wp;
	
	    if( !preg_match( '/^media\/(.*)/', $wp->request ) && isset( $wp->query_vars['attachment'] ) ) {
	        wp_redirect( site_url( '/media/' . $wp->query_vars['attachment'] ) , 301 );
	    }
	}