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<title>Get and/or set the current session name</title>
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<div class="refnamediv">
<h1 class="refname">session_name</h1>
<p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">session_name</span> — <span class="dc-title">Get and/or set the current session name</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.session-name-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">string</span> <span class="methodname"><strong>session_name</strong></span>
([ <span class="methodparam"><span class="type">string</span> <code class="parameter">$name</code></span>
] )</div>
<p class="para rdfs-comment">
<span class="function"><strong>session_name()</strong></span> returns the name of the current
session. If <code class="parameter">name</code> is given,
<span class="function"><strong>session_name()</strong></span> will update the session name and return
the <em class="emphasis">old</em> session name.
</p>
<p class="para">
If a new session <code class="parameter">name</code> is
supplied, <span class="function"><strong>session_name()</strong></span> modifies the HTTP cookie
(and output content when <em>session.transid</em> is
enabled). Once the HTTP cookie is
sent, <span class="function"><strong>session_name()</strong></span> raises error.
<span class="function"><strong>session_name()</strong></span> must be called
before <span class="function"><a href="function.session-start.html" class="function">session_start()</a></span> for the session to work
properly.
</p>
<p class="para">
The session name is reset to the default value stored in
<em>session.name</em> at request startup time. Thus, you need to
call <span class="function"><strong>session_name()</strong></span> for every request (and before
<span class="function"><a href="function.session-start.html" class="function">session_start()</a></span> is called).
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.session-name-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<code class="parameter">name</code></dt>
<dd>
<p class="para">
The session name references the name of the session, which is
used in cookies and URLs (e.g. <em>PHPSESSID</em>). It
should contain only alphanumeric characters; it should be short and
descriptive (i.e. for users with enabled cookie warnings).
If <code class="parameter">name</code> is specified, the name of the current
session is changed to its value.
</p>
<p class="para">
<div class="warning"><strong class="warning">Warning</strong>
<p class="para">
The session name can't consist of digits only, at least one letter
must be present. Otherwise a new session id is generated every time.
</p>
</div>
</p>
</dd>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.session-name-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns the name of the current session. If <code class="parameter">name</code> is given
and function updates the session name, name of the <em class="emphasis">old</em> session
is returned.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.session-name-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-5962">
<p><strong>Example #1 <span class="function"><strong>session_name()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /><br /></span><span style="color: #FF8000">/* set the session name to WebsiteID */<br /><br /></span><span style="color: #0000BB">$previous_name </span><span style="color: #007700">= </span><span style="color: #0000BB">session_name</span><span style="color: #007700">(</span><span style="color: #DD0000">"WebsiteID"</span><span style="color: #007700">);<br /><br />echo </span><span style="color: #DD0000">"The previous session name was </span><span style="color: #0000BB">$previous_name</span><span style="color: #DD0000"><br />"</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.session-name-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>7.2.0</td>
<td>
<span class="function"><strong>session_name()</strong></span> checks session status,
previously it only checked cookie status. Therefore,
older <span class="function"><strong>session_name()</strong></span> allows to
call <span class="function"><strong>session_name()</strong></span>
after <span class="function"><a href="function.session-start.html" class="function">session_start()</a></span> which may crash PHP
and may result in misbehaviors.
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.session-name-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member">
The <a href="session.configuration.html#ini.session.name" class="link">session.name</a> configuration
directive
</li>
</ul>
</p>
</div>
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