Based on kernel version 4.7.2. Page generated on 2016-08-22 22:45 EST.
1 <refentry id="media-func-open"> 2 <refmeta> 3 <refentrytitle>media open()</refentrytitle> 4 &manvol; 5 </refmeta> 6 7 <refnamediv> 8 <refname>media-open</refname> 9 <refpurpose>Open a media device</refpurpose> 10 </refnamediv> 11 12 <refsynopsisdiv> 13 <funcsynopsis> 14 <funcsynopsisinfo>#include <fcntl.h></funcsynopsisinfo> 15 <funcprototype> 16 <funcdef>int <function>open</function></funcdef> 17 <paramdef>const char *<parameter>device_name</parameter></paramdef> 18 <paramdef>int <parameter>flags</parameter></paramdef> 19 </funcprototype> 20 </funcsynopsis> 21 </refsynopsisdiv> 22 23 <refsect1> 24 <title>Arguments</title> 25 26 <variablelist> 27 <varlistentry> 28 <term><parameter>device_name</parameter></term> 29 <listitem> 30 <para>Device to be opened.</para> 31 </listitem> 32 </varlistentry> 33 <varlistentry> 34 <term><parameter>flags</parameter></term> 35 <listitem> 36 <para>Open flags. Access mode must be either <constant>O_RDONLY</constant> 37 or <constant>O_RDWR</constant>. Other flags have no effect.</para> 38 </listitem> 39 </varlistentry> 40 </variablelist> 41 </refsect1> 42 <refsect1> 43 <title>Description</title> 44 <para>To open a media device applications call <function>open()</function> 45 with the desired device name. The function has no side effects; the device 46 configuration remain unchanged.</para> 47 <para>When the device is opened in read-only mode, attempts to modify its 48 configuration will result in an error, and <varname>errno</varname> will be 49 set to <errorcode>EBADF</errorcode>.</para> 50 </refsect1> 51 <refsect1> 52 <title>Return Value</title> 53 54 <para><function>open</function> returns the new file descriptor on success. 55 On error, -1 is returned, and <varname>errno</varname> is set appropriately. 56 Possible error codes are:</para> 57 58 <variablelist> 59 <varlistentry> 60 <term><errorcode>EACCES</errorcode></term> 61 <listitem> 62 <para>The requested access to the file is not allowed.</para> 63 </listitem> 64 </varlistentry> 65 <varlistentry> 66 <term><errorcode>EMFILE</errorcode></term> 67 <listitem> 68 <para>The process already has the maximum number of files open. 69 </para> 70 </listitem> 71 </varlistentry> 72 <varlistentry> 73 <term><errorcode>ENFILE</errorcode></term> 74 <listitem> 75 <para>The system limit on the total number of open files has been 76 reached.</para> 77 </listitem> 78 </varlistentry> 79 <varlistentry> 80 <term><errorcode>ENOMEM</errorcode></term> 81 <listitem> 82 <para>Insufficient kernel memory was available.</para> 83 </listitem> 84 </varlistentry> 85 <varlistentry> 86 <term><errorcode>ENXIO</errorcode></term> 87 <listitem> 88 <para>No device corresponding to this device special file exists. 89 </para> 90 </listitem> 91 </varlistentry> 92 </variablelist> 93 </refsect1> 94 </refentry>
