forked from Minki/linux
[media] DocBook media: rewrite frontend open/close
To fix the last xmllint errors the open and close function reference description was rewritten based on the v4l2 open and close functions. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
This commit is contained in:
Hans Verkuil
Mauro Carvalho Chehab
parent
595d041a18
commit
dc9ef7d112
@ -59,11 +59,54 @@ specification is available at
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<section id="frontend_fcalls">
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<section id="frontend_fcalls">
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<title>Frontend Function Calls</title>
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<title>Frontend Function Calls</title>
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<section id="frontend_f_open">
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<refentry id="frontend_f_open">
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<title>open()</title>
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<refmeta>
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<para>DESCRIPTION</para>
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<refentrytitle>open()</refentrytitle>
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<informaltable><tgroup cols="1"><tbody><row>
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&manvol;
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<entry align="char">
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</refmeta>
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<refnamediv>
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<refname>fe-open</refname>
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<refpurpose>Open a frontend device</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<funcsynopsis>
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<funcsynopsisinfo>#include <fcntl.h></funcsynopsisinfo>
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<funcprototype>
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<funcdef>int <function>open</function></funcdef>
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<paramdef>const char *<parameter>device_name</parameter></paramdef>
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<paramdef>int <parameter>flags</parameter></paramdef>
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</funcprototype>
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</funcsynopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Arguments</title>
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<variablelist>
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<varlistentry>
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<term><parameter>device_name</parameter></term>
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<listitem>
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<para>Device to be opened.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>flags</parameter></term>
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<listitem>
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<para>Open flags. Access mode must be
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<constant>O_RDWR</constant>. This is just a technicality, input devices
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still support only reading and output devices only writing.</para>
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<para>When the <constant>O_NONBLOCK</constant> flag is
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given, the read() function will return the &EAGAIN; when no data is available,
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otherwise these functions block until data becomes
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available. Other flags have no effect.</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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<refsect1>
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<title>Description</title>
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<para>This system call opens a named frontend device (/dev/dvb/adapter0/frontend0)
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<para>This system call opens a named frontend device (/dev/dvb/adapter0/frontend0)
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for subsequent use. Usually the first thing to do after a successful open is to
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for subsequent use. Usually the first thing to do after a successful open is to
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find out the frontend type with <link linkend="FE_GET_INFO">FE_GET_INFO</link>.</para>
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find out the frontend type with <link linkend="FE_GET_INFO">FE_GET_INFO</link>.</para>
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@ -82,127 +125,121 @@ specification is available at
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for use in the specified mode. This implies that the corresponding hardware is
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for use in the specified mode. This implies that the corresponding hardware is
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powered up, and that other front-ends may have been powered down to make
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powered up, and that other front-ends may have been powered down to make
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that possible.</para>
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that possible.</para>
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</entry>
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</refsect1>
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</row></tbody></tgroup></informaltable>
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<para>SYNOPSIS</para>
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<refsect1>
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<informaltable><tgroup cols="1"><tbody><row><entry
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<title>Return Value</title>
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align="char">
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<para>int open(const char ⋆deviceName, int flags);</para>
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</entry>
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</row></tbody></tgroup></informaltable>
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<para>PARAMETERS
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</para>
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<informaltable><tgroup cols="2"><tbody><row><entry
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align="char">
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<para>const char
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*deviceName</para>
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</entry><entry
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align="char">
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<para>Name of specific video device.</para>
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</entry>
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</row><row><entry
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align="char">
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<para>int flags</para>
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</entry><entry
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align="char">
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<para>A bit-wise OR of the following flags:</para>
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</entry>
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</row><row><entry
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align="char">
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</entry><entry
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align="char">
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<para>O_RDONLY read-only access</para>
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</entry>
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</row><row><entry
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align="char">
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</entry><entry
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align="char">
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<para>O_RDWR read/write access</para>
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</entry>
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</row><row><entry
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align="char">
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</entry><entry
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align="char">
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<para>O_NONBLOCK open in non-blocking mode</para>
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</entry>
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</row><row><entry
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align="char">
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</entry><entry
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align="char">
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<para>(blocking mode is the default)</para>
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</entry>
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</row></tbody></tgroup></informaltable>
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<para>RETURN VALUE</para>
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<informaltable><tgroup cols="2"><tbody><row><entry
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align="char">
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<para>ENODEV</para>
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</entry><entry
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align="char">
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<para>Device driver not loaded/available.</para>
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</entry>
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</row><row><entry
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align="char">
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<para>EINTERNAL</para>
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</entry><entry
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align="char">
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<para>Internal error.</para>
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</entry>
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</row><row><entry
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align="char">
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<para>EBUSY</para>
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</entry><entry
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align="char">
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<para>Device or resource busy.</para>
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</entry>
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</row><row><entry
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align="char">
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<para>EINVAL</para>
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</entry><entry
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align="char">
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<para>Invalid argument.</para>
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</entry>
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</row></tbody></tgroup></informaltable>
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</section>
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<section id="frontend_f_close">
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<para>On success <function>open</function> returns the new file
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<title>close()</title>
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descriptor. On error -1 is returned, and the <varname>errno</varname>
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<para>DESCRIPTION
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variable is set appropriately. Possible error codes are:</para>
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</para>
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<informaltable><tgroup cols="1"><tbody><row><entry
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<variablelist>
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align="char">
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<varlistentry>
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<term><errorcode>EACCES</errorcode></term>
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<listitem>
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<para>The caller has no permission to access the
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device.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><errorcode>EBUSY</errorcode></term>
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<listitem>
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<para>The driver does not support multiple opens and the
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device is already in use.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><errorcode>ENXIO</errorcode></term>
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<listitem>
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<para>No device corresponding to this device special file
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exists.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><errorcode>ENOMEM</errorcode></term>
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<listitem>
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<para>Not enough kernel memory was available to complete the
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request.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><errorcode>EMFILE</errorcode></term>
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<listitem>
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<para>The process already has the maximum number of
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files open.</para>
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</listitem>
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</varlistentry>
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<varlistentry>
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<term><errorcode>ENFILE</errorcode></term>
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<listitem>
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<para>The limit on the total number of files open on the
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system has been reached.</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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</refentry>
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<refentry id="frontend_f_close">
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<refmeta>
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<refentrytitle>close()</refentrytitle>
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&manvol;
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</refmeta>
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<refnamediv>
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<refname>fe-close</refname>
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<refpurpose>Close a frontend device</refpurpose>
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</refnamediv>
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<refsynopsisdiv>
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<funcsynopsis>
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<funcsynopsisinfo>#include <unistd.h></funcsynopsisinfo>
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<funcprototype>
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<funcdef>int <function>close</function></funcdef>
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<paramdef>int <parameter>fd</parameter></paramdef>
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</funcprototype>
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</funcsynopsis>
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</refsynopsisdiv>
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<refsect1>
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<title>Arguments</title>
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<variablelist>
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<varlistentry>
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<term><parameter>fd</parameter></term>
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<listitem>
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<para>&fd;</para>
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</listitem>
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</varlistentry>
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</variablelist>
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</refsect1>
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<refsect1>
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<title>Description</title>
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<para>This system call closes a previously opened front-end device. After closing
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<para>This system call closes a previously opened front-end device. After closing
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a front-end device, its corresponding hardware might be powered down
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a front-end device, its corresponding hardware might be powered down
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automatically.</para>
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automatically.</para>
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</entry>
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</refsect1>
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</row></tbody></tgroup></informaltable>
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<refsect1>
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<para>SYNOPSIS
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<title>Return Value</title>
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</para>
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<informaltable><tgroup cols="1"><tbody><row><entry
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<para>The function returns <returnvalue>0</returnvalue> on
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align="char">
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success, <returnvalue>-1</returnvalue> on failure and the
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<para>int close(int fd);</para>
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<varname>errno</varname> is set appropriately. Possible error
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</entry>
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codes:</para>
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</row></tbody></tgroup></informaltable>
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<para>PARAMETERS
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<variablelist>
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</para>
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<varlistentry>
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<informaltable><tgroup cols="2"><tbody><row><entry
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<term><errorcode>EBADF</errorcode></term>
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align="char">
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<listitem>
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<para>int fd</para>
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<para><parameter>fd</parameter> is not a valid open file
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</entry><entry
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descriptor.</para>
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align="char">
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</listitem>
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<para>File descriptor returned by a previous call to open().</para>
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</varlistentry>
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</entry>
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</variablelist>
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</row></tbody></tgroup></informaltable>
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</refsect1>
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<para>RETURN VALUE</para>
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</refentry>
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<informaltable><tgroup cols="2"><tbody><row><entry
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align="char">
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<para>EBADF</para>
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</entry><entry
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align="char">
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<para>fd is not a valid open file descriptor.</para>
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</entry>
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</row></tbody></tgroup></informaltable>
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</section>
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&sub-fe-get-info;
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&sub-fe-get-info;
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&sub-fe-read-status;
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&sub-fe-read-status;
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