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<h1 class="refname">gzencode</h1>
<p class="verinfo">(PHP 4 >= 4.0.4, PHP 5)</p><p class="refpurpose"><span class="refname">gzencode</span> — <span class="dc-title">Create a gzip compressed string</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.gzencode-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">string</span> <span class="methodname"><strong>gzencode</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$data</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$level</code><span class="initializer"> = -1</span></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$encoding_mode</code><span class="initializer"> = FORCE_GZIP</span></span>
]] )</div>
<p class="para rdfs-comment">
This function returns a compressed version of the input
<em><code class="parameter">data</code></em> compatible with the output of the
<strong class="command">gzip</strong> program.
</p>
<p class="para">
For more information on the GZIP file format, see the document:
<a href="http://www.faqs.org/rfcs/rfc1952" class="link external">» GZIP file format specification
version 4.3</a> (RFC 1952).
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.gzencode-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">data</code></em></span>
<dd>
<p class="para">
The data to encode.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">level</code></em></span>
<dd>
<p class="para">
The level of compression. Can be given as 0 for no compression up to 9
for maximum compression. If not given, the default compression level will
be the default compression level of the zlib library.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">encoding_mode</code></em></span>
<dd>
<p class="para">
The encoding mode. Can be <strong><code>FORCE_GZIP</code></strong> (the default)
or <strong><code>FORCE_DEFLATE</code></strong>.
</p>
<p class="para">
Prior to PHP 5.4.0, using <strong><code>FORCE_DEFLATE</code></strong> results in
a standard zlib deflated string (inclusive zlib headers) after a gzip
file header but without the trailing crc32 checksum.
</p>
<p class="para">
In PHP 5.4.0 and later, <strong><code>FORCE_DEFLATE</code></strong> generates
RFC 1950 compliant output, consisting of a zlib header, the deflated
data, and an Adler checksum.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.gzencode-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
The encoded string, or <strong><code>FALSE</code></strong> if an error occurred.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.gzencode-changelog">
<h3 class="title">Changelog</h3>
<p class="para">
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>5.4.0</td>
<td>
<strong><code>FORCE_DEFLATE</code></strong> now generates RFC 1950 compliant
output.
</td>
</tr>
<tr>
<td>4.2.0</td>
<td>
The <em><code class="parameter">encoding_mode</code></em> parameter was added
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.gzencode-examples">
<h3 class="title">Examples</h3>
<p class="para">
The resulting data contains the appropriate headers and data
structure to make a standard .gz file, e.g.:
<div class="example" id="example-814">
<p><strong>Example #1 Creating a gzip file</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$data </span><span style="color: #007700">= </span><span style="color: #0000BB">implode</span><span style="color: #007700">(</span><span style="color: #DD0000">""</span><span style="color: #007700">, </span><span style="color: #0000BB">file</span><span style="color: #007700">(</span><span style="color: #DD0000">"bigfile.txt"</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">$gzdata </span><span style="color: #007700">= </span><span style="color: #0000BB">gzencode</span><span style="color: #007700">(</span><span style="color: #0000BB">$data</span><span style="color: #007700">, </span><span style="color: #0000BB">9</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$fp </span><span style="color: #007700">= </span><span style="color: #0000BB">fopen</span><span style="color: #007700">(</span><span style="color: #DD0000">"bigfile.txt.gz"</span><span style="color: #007700">, </span><span style="color: #DD0000">"w"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">fwrite</span><span style="color: #007700">(</span><span style="color: #0000BB">$fp</span><span style="color: #007700">, </span><span style="color: #0000BB">$gzdata</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">fclose</span><span style="color: #007700">(</span><span style="color: #0000BB">$fp</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.gzencode-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.gzdecode.html" class="function" rel="rdfs-seeAlso">gzdecode()</a> - Decodes a gzip compressed string</span></li>
<li class="member"> <span class="function"><a href="function.gzdeflate.html" class="function" rel="rdfs-seeAlso">gzdeflate()</a> - Deflate a string</span></li>
<li class="member"> <span class="function"><a href="function.gzinflate.html" class="function" rel="rdfs-seeAlso">gzinflate()</a> - Inflate a deflated string</span></li>
<li class="member"> <span class="function"><a href="function.gzuncompress.html" class="function" rel="rdfs-seeAlso">gzuncompress()</a> - Uncompress a compressed string</span></li>
<li class="member"> <span class="function"><a href="function.gzcompress.html" class="function" rel="rdfs-seeAlso">gzcompress()</a> - Compress a string</span></li>
<li class="member">
<a href="http://www.faqs.org/rfcs/rfc1950" class="link external">»
ZLIB Compressed Data Format Specification (RFC 1950)
</a>
</li>
</ul>
</p>
</div>
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