/php/function.microtime.html
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- <title>返回当前 Unix 时间戳和微秒数</title>
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- </div><hr /><div id="function.microtime" class="refentry">
- <div class="refnamediv">
- <h1 class="refname">microtime</h1>
- <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">microtime</span> — <span class="dc-title">返回当前 Unix 时间戳和微秒数</span></p>
- </div>
- <div class="refsect1 unknown-seealsp" id="refsect1-function.microtime-unknown-seealsp">
- <h3 class="title">说明</h3>
- <div class="methodsynopsis dc-description">
- <span class="type"><a href="language.pseudo-types.html#language.types.mixed" class="type mixed">mixed</a></span> <span class="methodname"><strong>microtime</strong></span>
- ([ <span class="methodparam"><span class="type">bool</span> <code class="parameter">$get_as_float</code></span>
- ] )</div>
- <p class="para rdfs-comment">
- <span class="function"><strong>microtime()</strong></span> 当前 Unix
- 时间戳以及微秒数。本函数仅在支持 gettimeofday()
- 系统调用的操作系统下可用。
- </p>
- <p class="para">
- 如果调用时不带可选参数,本函数以 "msec sec"
- 的格式返回一个字符串,其中 sec 是自 Unix 纪元(0:00:00 January 1,
- 1970 GMT)起到现在的秒数,msec 是微秒部分。字符串的两部分都是以秒为单位返回的。
- </p>
- <p class="para">
- 如果给出了 <em><code class="parameter">get_as_float</code></em> 参数并且其值等价于
- <strong><code>TRUE</code></strong>, <span class="function"><strong>microtime()</strong></span> 将返回一个浮点数。
- </p>
- <blockquote class="note"><p><strong class="note">Note</strong>:
- <span class="simpara">
- <em><code class="parameter">get_as_float</code></em> 参数是 PHP 5.0.0 新加的。
- </span>
- </p></blockquote>
- <p class="para">
- <div class="example" id="example-649">
- <p><strong>Example #1 用 <span class="function"><strong>microtime()</strong></span> 对脚本的运行计时</strong></p>
- <div class="example-contents">
- <div class="phpcode"><code><span style="color: #000000">
- <span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">/**<br /> * Simple function to replicate PHP 5 behaviour<br /> */<br /></span><span style="color: #007700">function </span><span style="color: #0000BB">microtime_float</span><span style="color: #007700">()<br />{<br /> list(</span><span style="color: #0000BB">$usec</span><span style="color: #007700">, </span><span style="color: #0000BB">$sec</span><span style="color: #007700">) = </span><span style="color: #0000BB">explode</span><span style="color: #007700">(</span><span style="color: #DD0000">" "</span><span style="color: #007700">, </span><span style="color: #0000BB">microtime</span><span style="color: #007700">());<br /> return ((float)</span><span style="color: #0000BB">$usec </span><span style="color: #007700">+ (float)</span><span style="color: #0000BB">$sec</span><span style="color: #007700">);<br />}<br /><br /></span><span style="color: #0000BB">$time_start </span><span style="color: #007700">= </span><span style="color: #0000BB">microtime_float</span><span style="color: #007700">();<br /><br /></span><span style="color: #FF8000">// Sleep for a while<br /></span><span style="color: #0000BB">usleep</span><span style="color: #007700">(</span><span style="color: #0000BB">100</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$time_end </span><span style="color: #007700">= </span><span style="color: #0000BB">microtime_float</span><span style="color: #007700">();<br /></span><span style="color: #0000BB">$time </span><span style="color: #007700">= </span><span style="color: #0000BB">$time_end </span><span style="color: #007700">- </span><span style="color: #0000BB">$time_start</span><span style="color: #007700">;<br /><br />echo </span><span style="color: #DD0000">"Did nothing in </span><span style="color: #0000BB">$time</span><span style="color: #DD0000"> seconds\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span>
- </span>
- </code></div>
- </div>
- </div>
- </p>
- <p class="para">
- 参见 <span class="function"><a href="function.time.html" class="function">time()</a></span>。
- </p>
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