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.. -*- coding: utf-8; mode: rst -*-
.. _cec-func-open:
**********
cec open()
**********
Name
====
cec-open - Open a cec device
Synopsis
========
.. code-block:: c
#include <fcntl.h>
.. c:function:: int open( const char *device_name, int flags )
:name: cec-open
Arguments
=========
``device_name``
Device to be opened.
``flags``
Open flags. Access mode must be ``O_RDWR``.
When the ``O_NONBLOCK`` flag is given, the
:ref:`CEC_RECEIVE <CEC_RECEIVE>` and :c:func:`CEC_DQEVENT` ioctls
will return the ``EAGAIN`` error code when no message or event is available, and
ioctls :ref:`CEC_TRANSMIT <CEC_TRANSMIT>`,
:ref:`CEC_ADAP_S_PHYS_ADDR <CEC_ADAP_S_PHYS_ADDR>` and
:ref:`CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>`
all return 0.
Other flags have no effect.
Description
===========
.. note::
This documents the proposed CEC API. This API is not yet finalized
and is currently only available as a staging kernel module.
To open a cec device applications call :c:func:`open()` with the
desired device name. The function has no side effects; the device
configuration remain unchanged.
When the device is opened in read-only mode, attempts to modify its
configuration will result in an error, and ``errno`` will be set to
EBADF.
Return Value
============
:c:func:`open()` returns the new file descriptor on success. On error,
-1 is returned, and ``errno`` is set appropriately. Possible error codes
include:
``EACCES``
The requested access to the file is not allowed.
``EMFILE``
The process already has the maximum number of files open.
``ENFILE``
The system limit on the total number of open files has been reached.
``ENOMEM``
Insufficient kernel memory was available.
``ENXIO``
No device corresponding to this device special file exists.
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