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                <h1>Fcntl</h1>
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            <h1>Fcntl</h1>


  <!--    -->
<ul><li><a href="#NAME">NAME</a><li><a href="#SYNOPSIS">SYNOPSIS</a><li><a href="#DESCRIPTION">DESCRIPTION</a><li><a href="#NOTE">NOTE</a><li><a href="#EXPORTED-SYMBOLS">EXPORTED SYMBOLS</a></ul><a name="NAME"></a><h1>NAME</h1>
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<p>Fcntl - load the C Fcntl.h defines</p>
<a name="SYNOPSIS"></a><h1>SYNOPSIS</h1>
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<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">Fcntl</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">Fcntl</span> <span class="q">qw(:DEFAULT :flock)</span><span class="sc">;</span></li></ol></pre><a name="DESCRIPTION"></a><h1>DESCRIPTION</h1>
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<p>This module is just a translation of the C <i>fcntl.h</i> file.
Unlike the old mechanism of requiring a translated <i>fcntl.ph</i>
file, this uses the <b>h2xs</b> program (see the Perl source distribution)
and your native C compiler.  This means that it has a 
far more likely chance of getting the numbers right.</p>
<a name="NOTE"></a><h1>NOTE</h1>
<p>Only <code class="inline"><span class="c">#define</span></code>
 symbols get translated; you must still correctly
pack up your own arguments to pass as args for locking functions, etc.</p>
<a name="EXPORTED-SYMBOLS"></a><h1>EXPORTED SYMBOLS</h1>
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<p>By default your system's F_* and O_* constants (eg, F_DUPFD and
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O_CREAT) and the FD_CLOEXEC constant are exported into your namespace.</p>
<p>You can request that the flock() constants (LOCK_SH, LOCK_EX, LOCK_NB
and LOCK_UN) be provided by using the tag <code class="inline"><span class="j">:</span><a class="l_k" href="functions/flock.html">flock</a></code>
.  See <a href="Exporter.html">Exporter</a>.</p>
<p>You can request that the old constants (FAPPEND, FASYNC, FCREAT,
FDEFER, FEXCL, FNDELAY, FNONBLOCK, FSYNC, FTRUNC) be provided for
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compatibility reasons by using the tag <code class="inline"><span class="j">:</span><span class="w">Fcompat</span></code>
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.  For new
applications the newer versions of these constants are suggested
(O_APPEND, O_ASYNC, O_CREAT, O_DEFER, O_EXCL, O_NDELAY, O_NONBLOCK,
O_SYNC, O_TRUNC).</p>
<p>For ease of use also the SEEK_* constants (for seek() and sysseek(),
e.g. SEEK_END) and the S_I* constants (for chmod() and stat()) are
available for import.  They can be imported either separately or using
the tags <code class="inline"><span class="j">:</span><a class="l_k" href="functions/seek.html">seek</a></code>
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 and <code class="inline"><span class="j">:</span><span class="w">mode</span></code>
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.</p>
<p>Please refer to your native fcntl(2), open(2), fseek(3), lseek(2)
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(equal to Perl's seek() and sysseek(), respectively), and chmod(2)
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documentation to see what constants are implemented in your system.</p>
<p>See <a href="perlopentut.html">perlopentut</a> to learn about the uses of the O_* constants
with sysopen().</p>
<p>See <a href="functions/seek.html">seek</a> and <a href="functions/sysseek.html">sysseek</a> about the SEEK_* constants.</p>
<p>See <a href="functions/stat.html">stat</a> about the S_I* constants.</p>
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