1.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
2.. c:namespace:: CEC
3
4.. _cec-func-open:
5
6**********
7cec open()
8**********
9
10Name
11====
12
13cec-open - Open a cec device
14
15Synopsis
16========
17
18.. code-block:: c
19
20    #include <fcntl.h>
21
22.. c:function:: int open( const char *device_name, int flags )
23
24Arguments
25=========
26
27``device_name``
28    Device to be opened.
29
30``flags``
31    Open flags. Access mode must be ``O_RDWR``.
32
33    When the ``O_NONBLOCK`` flag is given, the
34    :ref:`CEC_RECEIVE <CEC_RECEIVE>` and :ref:`CEC_DQEVENT <CEC_DQEVENT>` ioctls
35    will return the ``EAGAIN`` error code when no message or event is available, and
36    ioctls :ref:`CEC_TRANSMIT <CEC_TRANSMIT>`,
37    :ref:`CEC_ADAP_S_PHYS_ADDR <CEC_ADAP_S_PHYS_ADDR>` and
38    :ref:`CEC_ADAP_S_LOG_ADDRS <CEC_ADAP_S_LOG_ADDRS>`
39    all return 0.
40
41    Other flags have no effect.
42
43Description
44===========
45
46To open a cec device applications call :c:func:`open()` with the
47desired device name. The function has no side effects; the device
48configuration remain unchanged.
49
50When the device is opened in read-only mode, attempts to modify its
51configuration will result in an error, and ``errno`` will be set to
52EBADF.
53
54Return Value
55============
56
57:c:func:`open()` returns the new file descriptor on success. On error,
58-1 is returned, and ``errno`` is set appropriately. Possible error codes
59include:
60
61``EACCES``
62    The requested access to the file is not allowed.
63
64``EMFILE``
65    The process already has the maximum number of files open.
66
67``ENFILE``
68    The system limit on the total number of open files has been reached.
69
70``ENOMEM``
71    Insufficient kernel memory was available.
72
73``ENXIO``
74    No device corresponding to this device special file exists.
75