12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273 |
- <refentry id="media-func-ioctl">
- <refmeta>
- <refentrytitle>media ioctl()</refentrytitle>
- &manvol;
- </refmeta>
- <refnamediv>
- <refname>media-ioctl</refname>
- <refpurpose>Control a media device</refpurpose>
- </refnamediv>
- <refsynopsisdiv>
- <funcsynopsis>
- <funcsynopsisinfo>#include <sys/ioctl.h></funcsynopsisinfo>
- <funcprototype>
- <funcdef>int <function>ioctl</function></funcdef>
- <paramdef>int <parameter>fd</parameter></paramdef>
- <paramdef>int <parameter>request</parameter></paramdef>
- <paramdef>void *<parameter>argp</parameter></paramdef>
- </funcprototype>
- </funcsynopsis>
- </refsynopsisdiv>
- <refsect1>
- <title>Arguments</title>
- <variablelist>
- <varlistentry>
- <term><parameter>fd</parameter></term>
- <listitem>
- <para>&fd;</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><parameter>request</parameter></term>
- <listitem>
- <para>Media ioctl request code as defined in the media.h header file,
- for example MEDIA_IOC_SETUP_LINK.</para>
- </listitem>
- </varlistentry>
- <varlistentry>
- <term><parameter>argp</parameter></term>
- <listitem>
- <para>Pointer to a request-specific structure.</para>
- </listitem>
- </varlistentry>
- </variablelist>
- </refsect1>
- <refsect1>
- <title>Description</title>
- <para>The <function>ioctl()</function> function manipulates media device
- parameters. The argument <parameter>fd</parameter> must be an open file
- descriptor.</para>
- <para>The ioctl <parameter>request</parameter> code specifies the media
- 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
- <parameter>argp</parameter> in bytes.</para>
- <para>Macros and structures definitions specifying media ioctl requests and
- their parameters are located in the media.h header file. All media ioctl
- requests, their respective function and parameters are specified in
- <xref linkend="media-user-func" />.</para>
- </refsect1>
- <refsect1>
- &return-value;
- <para>Request-specific error codes are listed in the
- individual requests descriptions.</para>
- <para>When an ioctl that takes an output or read/write parameter fails,
- the parameter remains unmodified.</para>
- </refsect1>
- </refentry>
|