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            <h1>FileCache</h1>


  <!--    -->
<ul><li><a href="#NAME">NAME</a><li><a href="#SYNOPSIS">SYNOPSIS</a><li><a href="#DESCRIPTION">DESCRIPTION</a><li><a href="#CAVEATS">CAVEATS</a><li><a href="#BUGS">BUGS</a></ul><a name="NAME"></a><h1>NAME</h1>
<p>FileCache - keep more files open than the system permits</p>
<a name="SYNOPSIS"></a><h1>SYNOPSIS</h1>
<pre class="verbatim"><ol><li>    <a class="l_k" href="functions/no.html">no</a> <span class="w">strict</span> <span class="q">&#39;refs&#39;</span><span class="sc">;</span></li><li></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">FileCache</span><span class="sc">;</span></li><li>    <span class="c"># or</span></li><li>    <a class="l_k" href="functions/use.html">use</a> <span class="w">FileCache</span> <span class="w">maxopen</span> <span class="cm">=&gt;</span> <span class="n">16</span><span class="sc">;</span></li><li></li><li>    <span class="w">cacheout</span> <span class="i">$mode</span><span class="cm">,</span> <span class="i">$path</span><span class="sc">;</span></li><li>    <span class="c"># or</span></li><li>    <span class="w">cacheout</span> <span class="i">$path</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/print.html">print</a> <span class="i">$path</span> <span class="i">@data</span><span class="sc">;</span></li><li></li><li>    <span class="i">$fh</span> = <span class="w">cacheout</span> <span class="i">$mode</span><span class="cm">,</span> <span class="i">$path</span><span class="sc">;</span></li><li>    <span class="c"># or</span></li><li>    <span class="i">$fh</span> = <span class="w">cacheout</span> <span class="i">$path</span><span class="sc">;</span></li><li>    <a class="l_k" href="functions/print.html">print</a> <span class="i">$fh</span> <span class="i">@data</span><span class="sc">;</span></li></ol></pre><a name="DESCRIPTION"></a><h1>DESCRIPTION</h1>
<p>The <code class="inline"><span class="w">cacheout</span></code>
 function will make sure that there's a filehandle open
for reading or writing available as the pathname you give it. It
automatically closes and re-opens files if you exceed your system's
maximum number of file descriptors, or the suggested maximum <i>maxopen</i>.</p>
<ul>
<li><a name="cacheout-EXPR"></a><b>cacheout EXPR</b>
<p>The 1-argument form of cacheout will open a file for writing (<code class="inline"><span class="q">&#39;&gt;&#39;</span></code>
)
on it's first use, and appending (<code class="inline"><span class="q">&#39;&gt;&gt;&#39;</span></code>
) thereafter.</p>
<p>Returns EXPR on success for convenience. You may neglect the
return value and manipulate EXPR as the filehandle directly if you prefer.</p>
</li>
<li><a name="cacheout-MODE%2c-EXPR"></a><b>cacheout MODE, EXPR</b>
<p>The 2-argument form of cacheout will use the supplied mode for the initial
and subsequent openings. Most valid modes for 3-argument <code class="inline"><a class="l_k" href="functions/open.html">open</a></code> are supported
namely; <code class="inline"><span class="q">&#39;&gt;&#39;</span></code>
, <code class="inline"><span class="q">&#39;+&gt;&#39;</span></code>
, <code class="inline"><span class="q">&#39;&lt;&#39;</span></code>
, <code class="inline"><span class="q">&#39;&lt;+&#39;</span></code>
, <code class="inline"><span class="q">&#39;&gt;&gt;&#39;</span></code>
,
<code class="inline"> <span class="q">&#39;|-&#39;</span> </code>
 and <code class="inline"> <span class="q">&#39;-|&#39;</span> </code>
</p>
<p>To pass supplemental arguments to a program opened with <code class="inline"> <span class="q">&#39;|-&#39;</span> </code>
 or <code class="inline"> <span class="q">&#39;-|&#39;</span> </code>

append them to the command string as you would system EXPR.</p>
<p>Returns EXPR on success for convenience. You may neglect the
return value and manipulate EXPR as the filehandle directly if you prefer.</p>
</li>
</ul>
<a name="CAVEATS"></a><h1>CAVEATS</h1>
<p>While it is permissible to <code class="inline"><a class="l_k" href="functions/close.html">close</a></code> a FileCache managed file,
do not do so if you are calling <code class="inline"><span class="w">FileCache::cacheout</span></code>
 from a package other
than which it was imported, or with another module which overrides <code class="inline"><a class="l_k" href="functions/close.html">close</a></code>.
If you must, use <code class="inline"><span class="w">FileCache::cacheout_close</span></code>
.</p>
<p>Although FileCache can be used with piped opens ('-|' or '|-') doing so is
strongly discouraged.  If FileCache finds it necessary to close and then reopen
a pipe, the command at the far end of the pipe will be reexecuted - the results
of performing IO on FileCache'd pipes is unlikely to be what you expect.  The
ability to use FileCache on pipes may be removed in a future release.</p>
<p>FileCache does not store the current file offset if it finds it necessary to
close a file.  When the file is reopened, the offset will be as specified by the
original <code class="inline"><a class="l_k" href="functions/open.html">open</a></code> file mode.  This could be construed to be a bug.</p>
<p>The module functionality relies on symbolic references, so things will break
under 'use strict' unless 'no strict "refs"' is also specified.</p>
<a name="BUGS"></a><h1>BUGS</h1>
<p><i>sys/param.h</i> lies with its <code class="inline"><span class="w">NOFILE</span></code>
 define on some systems,
so you may have to set <i>maxopen</i> yourself.</p>




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