<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<refentry xml:id="function.dio-seek" xmlns="http://docbook.org/ns/docbook">
 <refnamediv>
  <refname>dio_seek</refname>
  <refpurpose>Seeks to pos on fd from whence</refpurpose>
 </refnamediv>
 <refsect1 role="description">
  &reftitle.description;
  <methodsynopsis>
   <type>int</type><methodname>dio_seek</methodname>
   <methodparam><type>resource</type><parameter>fd</parameter></methodparam>
   <methodparam><type>int</type><parameter>pos</parameter></methodparam>
   <methodparam choice="opt"><type>int</type><parameter>whence</parameter><initializer>SEEK_SET</initializer></methodparam>
  </methodsynopsis>
  <para>
   The function <function>dio_seek</function> is used to change the
   file position of the given file descriptor.  
  </para>
 </refsect1>
 <refsect1 role="parameters">
  &reftitle.parameters;
  <para>
   <variablelist>
    <varlistentry>
     <term><parameter>fd</parameter></term>
     <listitem>
      <para>
       The file descriptor returned by <function>dio_open</function>.
      </para>
     </listitem>
    </varlistentry>
    <varlistentry>
     <term><parameter>pos</parameter></term>
     <listitem>
      <para>
       The new position.
      </para>
     </listitem>
    </varlistentry>
    <varlistentry>
     <term><parameter>whence</parameter></term>
     <listitem>
      <para>
       Specifies how the position <parameter>pos</parameter> should be 
       interpreted:
       <itemizedlist>
        <listitem>
         <para>
          <constant>SEEK_SET</constant> (default) - specifies that 
          <parameter>pos</parameter> is specified from the beginning of the 
          file.
         </para>
        </listitem>
        <listitem>
         <para>
          <constant>SEEK_CUR</constant> - Specifies that 
          <parameter>pos</parameter> is a count of characters from the current
          file position. This count may be positive or negative.
         </para>
        </listitem>
        <listitem>
         <para>
          <constant>SEEK_END</constant> - Specifies that 
          <parameter>pos</parameter> is a count of characters from the end of
          the file. A negative count specifies a position within the current 
          extent of the file; a positive count specifies a position past the 
          current end. If you set the position past the current end, and 
          actually write data, you will extend the file with zeros up to that
          position.
         </para>
        </listitem>
       </itemizedlist>
      </para>
     </listitem>
    </varlistentry>
   </variablelist>
  </para>
 </refsect1>
 <refsect1 role="returnvalues">
  &reftitle.returnvalues;
  <para>
  </para>
 </refsect1>
 <refsect1 role="examples">
  &reftitle.examples;
  <para>
   <example>
    <title>Positioning in a file</title>
    <programlisting role="php">
<![CDATA[
<?php

$fd = dio_open('/dev/ttyS0', O_RDWR);

dio_seek($fd, 10, SEEK_SET);
// position is now at 10 characters from the start of the file

dio_seek($fd, -2, SEEK_CUR);
// position is now at 8 characters from the start of the file

dio_seek($fd, -5, SEEK_END);
// position is now at 5 characters from the end of the file

dio_seek($fd, 10, SEEK_END);
// position is now at 10 characters past the end of the file. 
// The 10 characters between the end of the file and the current
// position are filled with zeros.

dio_close($fd);
?>
]]>
    </programlisting>
   </example>     
  </para>
 </refsect1>
</refentry>

<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->
