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<div class="refnamediv">
<h1 class="refname">preg_quote</h1>
<p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">preg_quote</span> — <span class="dc-title">Quote regular expression characters</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.preg-quote-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">string</span> <span class="methodname"><strong>preg_quote</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$str</code></span>
[, <span class="methodparam"><span class="type">string</span> <code class="parameter">$delimiter</code><span class="initializer"> = <strong><code>NULL</code></strong></span></span>
] )</div>
<p class="para rdfs-comment">
<span class="function"><strong>preg_quote()</strong></span> takes <em><code class="parameter">str</code></em>
and puts a backslash in front of every character that is part of
the regular expression syntax. This is useful if you have a
run-time string that you need to match in some text and the
string may contain special regex characters.
</p>
<p class="para">
The special regular expression characters are:
<em>. \ + * ? [ ^ ] $ ( ) { } = ! < > | : -</em>
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.preg-quote-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">str</code></em></span>
<dd>
<p class="para">
The input string.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">delimiter</code></em></span>
<dd>
<p class="para">
If the optional <em><code class="parameter">delimiter</code></em> is specified, it
will also be escaped. This is useful for escaping the delimiter
that is required by the PCRE functions. The / is the most commonly
used delimiter.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.preg-quote-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns the quoted (escaped) string.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.preg-quote-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>5.3.0</td>
<td>
The <em>-</em> character is now quoted
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.preg-quote-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-4792">
<p><strong>Example #1 <span class="function"><strong>preg_quote()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$keywords </span><span style="color: #007700">= </span><span style="color: #DD0000">'$40 for a g3/400'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$keywords </span><span style="color: #007700">= </span><span style="color: #0000BB">preg_quote</span><span style="color: #007700">(</span><span style="color: #0000BB">$keywords</span><span style="color: #007700">, </span><span style="color: #DD0000">'/'</span><span style="color: #007700">);<br />echo </span><span style="color: #0000BB">$keywords</span><span style="color: #007700">; </span><span style="color: #FF8000">// returns \$40 for a g3\/400<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
<p class="para">
<div class="example" id="example-4793">
<p><strong>Example #2 Italicizing a word within some text</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// In this example, preg_quote($word) is used to keep the<br />// asterisks from having special meaning to the regular<br />// expression.<br /><br /></span><span style="color: #0000BB">$textbody </span><span style="color: #007700">= </span><span style="color: #DD0000">"This book is *very* difficult to find."</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$word </span><span style="color: #007700">= </span><span style="color: #DD0000">"*very*"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$textbody </span><span style="color: #007700">= </span><span style="color: #0000BB">preg_replace </span><span style="color: #007700">(</span><span style="color: #DD0000">"/" </span><span style="color: #007700">. </span><span style="color: #0000BB">preg_quote</span><span style="color: #007700">(</span><span style="color: #0000BB">$word</span><span style="color: #007700">) . </span><span style="color: #DD0000">"/"</span><span style="color: #007700">,<br /> </span><span style="color: #DD0000">"<i>" </span><span style="color: #007700">. </span><span style="color: #0000BB">$word </span><span style="color: #007700">. </span><span style="color: #DD0000">"</i>"</span><span style="color: #007700">,<br /> </span><span style="color: #0000BB">$textbody</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</p>
</div>
<div class="refsect1 notes" id="refsect1-function.preg-quote-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>: <span class="simpara">This function is
binary-safe.</span></p></blockquote>
</div>
<div class="refsect1 seealso" id="refsect1-function.preg-quote-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"><a href="pcre.pattern.html" class="link">PCRE Patterns</a></li>
<li class="member"> <span class="function"><a href="function.escapeshellcmd.html" class="function" rel="rdfs-seeAlso">escapeshellcmd()</a> - Escape shell metacharacters</span></li>
</ul>
</p>
</div>
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