<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <title>Compress a string</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.gzclose.html">gzclose</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.gzdecode.html">gzdecode</a></div> <div class="up"><a href="ref.zlib.html">Zlib Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="function.gzcompress" class="refentry"> <div class="refnamediv"> <h1 class="refname">gzcompress</h1> <p class="verinfo">(PHP 4 >= 4.0.1, PHP 5)</p><p class="refpurpose"><span class="refname">gzcompress</span> — <span class="dc-title">Compress a string</span></p> </div> <div class="refsect1 description" id="refsect1-function.gzcompress-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">string</span> <span class="methodname"><strong>gzcompress</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</code><span class="initializer"> = ZLIB_ENCODING_DEFLATE</span></span> ]] )</div> <p class="para rdfs-comment"> This function compress the given string using the <em>ZLIB</em> data format. </p> <p class="para"> For details on the ZLIB compression algorithm see the document "<a href="http://www.faqs.org/rfcs/rfc1950" class="link external">» ZLIB Compressed Data Format Specification version 3.3</a>" (RFC 1950). </p> <blockquote class="note"><p><strong class="note">Note</strong>: <p class="para"> This is <em class="emphasis">not</em> the same as gzip compression, which includes some header data. See <span class="function"><a href="function.gzencode.html" class="function">gzencode()</a></span> for gzip compression. </p> </p></blockquote> </div> <div class="refsect1 parameters" id="refsect1-function.gzcompress-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 compress. </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. </p> <p class="para"> If -1 is used, the default compression of the zlib library is used which is 6. </p> </dd> </dt> <dt> <span class="term"><em><code class="parameter">encoding</code></em></span> <dd> <p class="para"> One of <strong><code>ZLIB_ENCODING_*</code></strong> constants. </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues" id="refsect1-function.gzcompress-returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> The compressed string or <strong><code>FALSE</code></strong> if an error occurred. </p> </div> <div class="refsect1 examples" id="refsect1-function.gzcompress-examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example" id="example-812"> <p><strong>Example #1 <span class="function"><strong>gzcompress()</strong></span> example</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br />$compressed </span><span style="color: #007700">= </span><span style="color: #0000BB">gzcompress</span><span style="color: #007700">(</span><span style="color: #DD0000">'Compress me'</span><span style="color: #007700">, </span><span style="color: #0000BB">9</span><span style="color: #007700">);<br />echo </span><span style="color: #0000BB">$compressed</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> </div> </p> </div> <div class="refsect1 changelog" id="refsect1-function.gzcompress-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> Added <em><code class="parameter">encoding</code></em> parameter. </td> </tr> </tbody> </table> </p> </div> <div class="refsect1 seealso" id="refsect1-function.gzcompress-seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <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.gzencode.html" class="function" rel="rdfs-seeAlso">gzencode()</a> - Create a gzip compressed string</span></li> </ul> </p> </div> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.gzclose.html">gzclose</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.gzdecode.html">gzdecode</a></div> <div class="up"><a href="ref.zlib.html">Zlib Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div></body></html>