.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later .. c:namespace:: CEC

.. _cec-func-ioctl:

cec ioctl()

Name

cec-ioctl - Control a cec device

Synopsis

.. code-block:: c

#include <sys/ioctl.h>

int ioctl(int fd, int request, void *argp)

Arguments

fd File descriptor returned by :c:func:open().

request CEC ioctl request code as defined in the cec.h header file, for example :ref:CEC_ADAP_G_CAPS <CEC_ADAP_G_CAPS>.

argp Pointer to a request-specific structure.

Description

The :c:func:ioctl() function manipulates cec device parameters. The argument fd must be an open file descriptor.

The ioctl request code specifies the cec function to be called. It has encoded in it whether the argument is an input, output or read/write parameter, and the size of the argument argp in bytes.

Macros and structures definitions specifying cec ioctl requests and their parameters are located in the cec.h header file. All cec ioctl requests, their respective function and parameters are specified in :ref:cec-user-func.

Return Value

On success 0 is returned, on error -1 and the errno variable is set appropriately. The generic error codes are described at the :ref:Generic Error Codes <gen-errors> chapter.

Request-specific error codes are listed in the individual requests descriptions.

When an ioctl that takes an output or read/write parameter fails, the parameter remains unmodified.