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<title>Checks the existence of a node in zookeeper synchronously</title>
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<div class="refnamediv">
<h1 class="refname">Zookeeper::exists</h1>
<p class="verinfo">(PECL zookeeper >= 0.1.0)</p><p class="refpurpose"><span class="refname">Zookeeper::exists</span> — <span class="dc-title">Checks the existence of a node in zookeeper synchronously</span></p>
</div>
<div class="refsect1 description" id="refsect1-zookeeper.exists-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="modifier">public</span>
<span class="type">bool</span> <span class="methodname"><strong>Zookeeper::exists</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$path</code></span>
[, <span class="methodparam"><span class="type"><a href="language.types.callable.html" class="type callable">callable</a></span> <code class="parameter">$watcher_cb</code><span class="initializer"> = <strong><code>NULL</code></strong></span></span>
] )</div>
</div>
<div class="refsect1 parameters" id="refsect1-zookeeper.exists-parameters">
<h3 class="title">Parameters</h3>
<dl>
<dt>
<code class="parameter">path</code></dt>
<dd>
<p class="para">
The name of the node. Expressed as a file name with slashes separating ancestors of the node.
</p>
</dd>
<dt>
<code class="parameter">watcher_cb</code></dt>
<dd>
<p class="para">
if nonzero, a watch will be set at the server to notify the client if the node changes. The watch will be set even if the node does not
</p>
</dd>
</dl>
</div>
<div class="refsect1 returnvalues" id="refsect1-zookeeper.exists-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns true/false on success, and false on failure.
</p>
</div>
<div class="refsect1 errors" id="refsect1-zookeeper.exists-errors">
<h3 class="title">Errors/Exceptions</h3>
<p class="para">
This method emits PHP error/warning when parameters count or types are wrong or fail to check the existence of a node.
</p>
<div class="caution"><strong class="caution">Caution</strong>
<p class="para">
Since version 0.3.0, this method emits <strong class="classname">ZookeeperException</strong> and it's derivatives.
</p>
</div>
</div>
<div class="refsect1 examples" id="refsect1-zookeeper.exists-examples">
<h3 class="title">Examples</h3>
<div class="example" id="example-5841">
<p><strong>Example #1 <span class="methodname"><strong>Zookeeper::exists()</strong></span> example</strong></p>
<div class="example-contents"><p>
Check the existence of a node.
</p></div>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$zookeeper </span><span style="color: #007700">= new </span><span style="color: #0000BB">Zookeeper</span><span style="color: #007700">(</span><span style="color: #DD0000">'locahost:2181'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$path </span><span style="color: #007700">= </span><span style="color: #DD0000">'/path/to/node'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$r </span><span style="color: #007700">= </span><span style="color: #0000BB">$zookeeper</span><span style="color: #007700">-></span><span style="color: #0000BB">exists</span><span style="color: #007700">(</span><span style="color: #0000BB">$path</span><span style="color: #007700">);<br />if (</span><span style="color: #0000BB">$r</span><span style="color: #007700">)<br /> echo </span><span style="color: #DD0000">'EXISTS'</span><span style="color: #007700">;<br />else<br /> echo </span><span style="color: #DD0000">'N/A or ERR'</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>The above example will output:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
EXISTS
</pre></div>
</div>
</div>
</div>
<div class="refsect1 seealso" id="refsect1-zookeeper.exists-seealso">
<h3 class="title">See Also</h3>
<ul class="simplelist">
<li class="member"><span class="methodname"><a href="zookeeper.get.html" class="methodname" rel="rdfs-seeAlso">Zookeeper::get()</a> - Gets the data associated with a node synchronously</span></li>
<li class="member"><strong class="classname">ZookeeperException</strong></li>
</ul>
</div>
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