Documentation/userspace-api/media/dvb/ca-get-msg.rst

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.. document under the terms of the GNU Free Documentation License,
.. Version 1.1 or any later version published by the Free Software
.. Foundation, with no Invariant Sections, no Front-Cover Texts
.. and no Back-Cover Texts. A copy of the license is included at
.. Documentation/userspace-api/media/fdl-appendix.rst.
..
.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections

.. _CA_GET_MSG:

==========
CA_GET_MSG
==========

Name
----

CA_GET_MSG


Synopsis
--------

.. c:function:: int ioctl(fd, CA_GET_MSG, struct ca_msg *msg)
    :name: CA_GET_MSG


Arguments
---------

``fd``
  File descriptor returned by a previous call to :c:func:`open() <dvb-ca-open>`.

``msg``
  Pointer to struct :c:type:`ca_msg`.

Description
-----------

Receives a message via a CI CA module.

.. note::

   Please notice that, on most drivers, this is done by reading from
   the /dev/adapter?/ca? device node.


Return Value
------------


On success 0 is returned.

On error -1 is returned, and the ``errno`` variable is set
appropriately.

Generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.