2011-09-13 17:44:24 +00:00
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<title>db_env_set_func_seek</title>
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<p>Library Version 11.2.5.2</p>
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<th colspan="3" align="center">db_env_set_func_seek</th>
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<td width="20%" align="left"><a accesskey="p" href="db_env_set_func_rename.html">Prev</a> </td>
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<th width="60%" align="center">Appendix C.
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Berkeley DB Application Space Static Functions
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</th>
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<td width="20%" align="right"> <a accesskey="n" href="db_env_set_func_unlink.html">Next</a></td>
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<h2 class="title" style="clear: both"><a id="db_env_set_func_seek"></a>db_env_set_func_seek</h2>
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</div>
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</div>
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<pre class="programlisting">#include <db.h>
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int
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db_env_set_func_seek(int (*func_seek)(int fd, off_t offset, int whence)); </pre>
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<p>
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The Berkeley DB library requires the ability to specify that a
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subsequent read from or write to a file will occur at a specific
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location in that file.
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</p>
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<p>
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The <code class="function">db_env_set_func_seek()</code> function configures all operations performed by
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a process and all of its threads of control, not operations confined
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to a single database environment.
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</p>
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<p>
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Although the <code class="function">db_env_set_func_seek()</code> function may be called at any time
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during the life of the application, it should normally be called
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before making calls to the <a class="xref" href="envcreate.html" title="db_env_create">db_env_create</a> or
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<a class="xref" href="dbcreate.html" title="db_create">db_create</a> methods.
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</p>
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<p>
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The <code class="function">db_env_set_func_seek()</code> <span>
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function returns a non-zero error value on failure and 0 on success.
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</span>
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</p>
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<div class="sect2" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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2011-12-20 00:07:10 +00:00
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<h3 class="title"><a id="id3775235"></a>Parameters</h3>
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2011-09-13 17:44:24 +00:00
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</div>
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</div>
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</div>
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<div class="sect3" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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2011-12-20 00:07:10 +00:00
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<h4 class="title"><a id="id3775238"></a>func_seek</h4>
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2011-09-13 17:44:24 +00:00
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</div>
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</div>
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</div>
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<p>
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The <span class="bold"><strong>func_seek</strong></span> parameter is the
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function which seeks to a specific location in a file.
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</p>
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<p>
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The <span class="bold"><strong>fd</strong></span> parameter is an open file
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descriptor on the file.
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</p>
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<p>
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The <span class="bold"><strong>seek</strong></span> function must cause a
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subsequent read from or write to the file to occur at the byte offset
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specified by the <span class="bold"><strong>offset</strong></span> parameter.
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</p>
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<p>
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The <span class="bold"><strong>whence</strong></span> parameter specifies where
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in the file the byte offset is relative to, as described by the
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IEEE/ANSI Std 1003.1 (POSIX) <span class="bold"><strong>lseek</strong></span>
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system call.
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</p>
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<p>
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The <span class="bold"><strong>func_seek</strong></span> function must return
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the value of <span class="bold"><strong>errno</strong></span> on failure and 0
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on success.
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</p>
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</div>
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</div>
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<div class="sect2" lang="en" xml:lang="en">
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<div class="titlepage">
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<div>
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<div>
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2011-12-20 00:07:10 +00:00
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<h3 class="title"><a id="id3775190"></a>See Also</h3>
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2011-09-13 17:44:24 +00:00
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</div>
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</div>
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<p>
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<a href="../../programmer_reference/program_runtime.html" class="olink">Run-time configuration</a>
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