.. highlightlang:: us

.. index:: updf_get_free_pages

.. _updf_get_free_pages:

updf_get_free_pages
===================

.. us.tag updf_get_free_pages NOTREADYENGLISH updf updf-stor New5500

:ref:`updf_get_free_pages` returns the number of unused pages in a UPDF file.

.. function:: nPages = updf_get_free_pages(stg)

.. us.return

**Return Value**

*nPages* number of unused pages.

.. us.params

**Parameters**

.. uparam:: stg

   *stg* is a storage object (see :ref:`updf_create_file`, :ref:`updf_open_file`,
   :ref:`updf_create_storage`).

.. us.comment

**Comment**

A UPDF file consists of pages with a size 1024 bytes each. If pages are deleted
the pages are set to empty and can be used again. If the file was created with
the ``UPDF_REPACKING`` flag the free pages will be removed when the document will
be closed. The packing process leads to performance loss if a large number of
free pages exist. In this case it mach faster to copy the storages and streams
into a new file using :ref:`updf_copy_to`.

.. us.history

**History**

.. list-table::
   :header-rows: 1

   * - Version
     - Description
   * - R2013 (5.50)
     - New.

.. seealso::
   :ref:`Overview-UPDF-Files`,
   :ref:`updf_create_file`,
   :ref:`updf_open_file`

:sub:`id-1760231`