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<h2 class="title" style="clear: both"><a id="dbfd"></a>Db::fd()</h2>
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<pre class="programlisting">#include <db_cxx.h>
int
Db::fd(int *fdp);</pre>
<p>
The <code class="methodname">Db::fd()</code> method provides access to a file descriptor
representative of the underlying database. A file descriptor
referring to the same file will be returned to all processes that call
<a class="xref" href="dbopen.html" title="Db::open()">Db::open()</a> with the same
<span class="bold"><strong>file</strong></span> parameter.
</p>
<p>
This file descriptor may be safely used as a parameter to the
<span class="bold"><strong>fcntl</strong></span>(2) and <span class="bold"><strong>flock</strong></span>(2) locking functions.
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<p>
The <code class="methodname">Db::fd()</code> method only supports a coarse-grained form of locking.
Applications should instead use the Berkeley DB lock manager where
possible.
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<p>
The <code class="methodname">Db::fd()</code> <span>
<span>
method either returns a non-zero error value or throws an
exception that encapsulates a non-zero error value on
failure, and returns 0 on success.
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<h4 class="title"><a id="idp1695888"></a>fdp</h4>
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The <span class="bold"><strong>fdp</strong></span> parameter references memory
into which the current file descriptor is copied.
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