<?php
include_once $_SERVER['DOCUMENT_ROOT'] . '/include/shared-manual.inc';
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include_once dirname(__FILE__) ."/toc/ref.session.inc";
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    0 => 'index.php',
    1 => 'PHP Manual',
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  'this' => 
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    0 => 'function.session-cache-expire.php',
    1 => 'session_cache_expire',
    2 => '返回/设置当前缓存的到期时间',
  ),
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    1 => 'Session 函数',
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manual_setup($setup);

contributors($setup);

?>
<div id="function.session-cache-expire" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">session_cache_expire</h1>
  <p class="verinfo">(PHP 4 &gt;= 4.2.0, PHP 5, PHP 7, PHP 8)</p><p class="refpurpose"><span class="refname">session_cache_expire</span> &mdash; <span class="dc-title">返回/设置当前缓存的到期时间</span></p>

 </div>
 
 <div class="refsect1 description" id="refsect1-function.session-cache-expire-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>session_cache_expire</strong></span>(<span class="methodparam"><span class="type"><span class="type"><a href="language.types.null.php" class="type null">?</a></span><span class="type"><a href="language.types.integer.php" class="type int">int</a></span></span> <code class="parameter">$value</code><span class="initializer"> = <strong><code><a href="reserved.constants.php#constant.null">null</a></code></strong></span></span>): <span class="type"><span class="type"><a href="language.types.integer.php" class="type int">int</a></span>|<span class="type"><a href="language.types.singleton.php" class="type false">false</a></span></span></div>

  <p class="para rdfs-comment">
   <span class="function"><strong>session_cache_expire()</strong></span> 返回
   <code class="literal">session.cache_expire</code> 的设定值。 
  </p>
  <p class="para">
   请求开始的时候，缓存到期时间会被重置为 180，并且保存在
   <a href="session.configuration.php#ini.session.cache-expire" class="link">session.cache_expire</a> 配置项中。
   因此，针对每个请求，需要在 <span class="function"><a href="function.session-start.php" class="function">session_start()</a></span> 函数调用之前
   调用 <span class="function"><strong>session_cache_expire()</strong></span> 来设置缓存到期时间。
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.session-cache-expire-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>
    
     <dt><code class="parameter">value</code></dt>
     <dd>
      <p class="para">
       如果指定 <code class="parameter">value</code> 且不为 <strong><code><a href="reserved.constants.php#constant.null">null</a></code></strong>，就使用
       <code class="parameter">value</code> 的值替换当前缓存到期时间。
      </p>
      <p class="para">
       <blockquote class="note"><p><strong class="note">注意</strong>: 
        <span class="simpara">
         仅在 <code class="literal">session.cache_limiter</code> 的设置值
         <em>不是</em> <code class="literal">nocache</code> 的时候，
         才可以设置 <code class="parameter">value</code> 参数。
        </span>
       </p></blockquote>
      </p>
     </dd>
    
   </dl>
  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.session-cache-expire-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   返回 <code class="literal">session.cache_expire</code> 的当前设置值，
   以分钟为单位，默认值是 180 （分钟）。如果更改值失败，则返回 <strong><code><a href="reserved.constants.php#constant.false">false</a></code></strong>。
  </p>
 </div>


 <div class="refsect1 changelog" id="refsect1-function.session-cache-expire-changelog">
  <h3 class="title">更新日志</h3>
  <table class="doctable informaltable">
   
    <thead>
     <tr>
      <th>版本</th>
      <th>说明</th>
     </tr>

    </thead>

    <tbody class="tbody">
     <tr>
      <td>8.0.0</td>
      <td>
       <code class="parameter">value</code> 现在可以为 null。
      </td>
     </tr>

    </tbody>
   
  </table>

 </div>


 <div class="refsect1 examples" id="refsect1-function.session-cache-expire-examples">
  <h3 class="title">示例</h3>
  <p class="para">
   <div class="example" id="example-1">
    <p><strong>示例 #1 <span class="function"><strong>session_cache_expire()</strong></span> 示例</strong></p>
    <div class="example-contents">
<div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB">&lt;?php<br /><br /></span><span style="color: #FF8000">/* 设置缓存限制为 “private” */<br /><br /></span><span style="color: #0000BB">session_cache_limiter</span><span style="color: #007700">(</span><span style="color: #DD0000">'private'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$cache_limiter </span><span style="color: #007700">= </span><span style="color: #0000BB">session_cache_limiter</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* 设置缓存过期时间为 30 分钟 */<br /></span><span style="color: #0000BB">session_cache_expire</span><span style="color: #007700">(</span><span style="color: #0000BB">30</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$cache_expire </span><span style="color: #007700">= </span><span style="color: #0000BB">session_cache_expire</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">/* 开始会话 */<br /><br /></span><span style="color: #0000BB">session_start</span><span style="color: #007700">();<br /><br />echo </span><span style="color: #DD0000">"The cache limiter is now set to </span><span style="color: #0000BB">$cache_limiter</span><span style="color: #DD0000">&lt;br /&gt;"</span><span style="color: #007700">;<br />echo </span><span style="color: #DD0000">"The cached session pages expire after </span><span style="color: #0000BB">$cache_expire</span><span style="color: #DD0000"> minutes"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?&gt;</span></span></code></div>
    </div>

   </div>
  </p>
 </div>


 <div class="refsect1 seealso" id="refsect1-function.session-cache-expire-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li><a href="session.configuration.php#ini.session.cache-expire" class="link">session.cache_expire</a></li>
    <li><a href="session.configuration.php#ini.session.cache-limiter" class="link">session.cache_limiter</a></li>
    <li><span class="function"><a href="function.session-cache-limiter.php" class="function" rel="rdfs-seeAlso">session_cache_limiter()</a> - 读取/设置缓存限制器</span></li>
   </ul>
  </p>
 </div>


</div><?php manual_footer($setup); ?>