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<title>Return current Unix timestamp with microseconds</title>
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<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">Return current Unix timestamp with microseconds</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.microtime-description">
<h3 class="title">Description</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 class="initializer"> = false</span></span>
] )</div>
<p class="para rdfs-comment">
<span class="function"><strong>microtime()</strong></span> returns the current Unix timestamp with
microseconds. This function is only available on operating systems that
support the gettimeofday() system call.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.microtime-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">get_as_float</code></em></span>
<dd>
<p class="para">
If used and set to <strong><code>TRUE</code></strong>, <span class="function"><strong>microtime()</strong></span> will return a
<span class="type"><a href="language.types.float.html" class="type float">float</a></span> instead of a <span class="type"><a href="language.types.string.html" class="type string">string</a></span>, as described in
the return values section below.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.microtime-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
By default, <span class="function"><strong>microtime()</strong></span> returns a <span class="type"><a href="language.types.string.html" class="type string">string</a></span> in
the form "msec sec", where <em>sec</em> is the number of seconds
since the Unix epoch (0:00:00 January 1,1970 GMT), and <em>msec</em>
measures microseconds that have elapsed since <em>sec</em>
and is also expressed in seconds.
</p>
<p class="para">
If <em><code class="parameter">get_as_float</code></em> is set to <strong><code>TRUE</code></strong>, then
<span class="function"><strong>microtime()</strong></span> returns a <span class="type"><a href="language.types.float.html" class="type float">float</a></span>, which
represents the current time in seconds since the Unix epoch accurate to the
nearest microsecond.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.microtime-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>5.0.0</td>
<td>
The <em><code class="parameter">get_as_float</code></em> parameter was added.
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.microtime-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-2312">
<p><strong>Example #1 Timing script execution with <span class="function"><strong>microtime()</strong></span></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">$time</span><span style="color: #DD0000"> seconds\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
<div class="example" id="example-2313">
<p><strong>Example #2 Timing script execution in PHP 5</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br />$time_start </span><span style="color: #007700">= </span><span style="color: #0000BB">microtime</span><span style="color: #007700">(</span><span style="color: #0000BB">true</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">$time_end </span><span style="color: #007700">= </span><span style="color: #0000BB">microtime</span><span style="color: #007700">(</span><span style="color: #0000BB">true</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$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>
<div class="example" id="example-2314">
<p><strong>Example #3 <span class="function"><strong>microtime()</strong></span> and <em>REQUEST_TIME_FLOAT</em> (as of PHP 5.4.0)</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">// Randomize sleeping time<br /></span><span style="color: #0000BB">usleep</span><span style="color: #007700">(</span><span style="color: #0000BB">mt_rand</span><span style="color: #007700">(</span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">10000</span><span style="color: #007700">));<br /><br /></span><span style="color: #FF8000">// As of PHP 5.4.0, REQUEST_TIME_FLOAT is available in the $_SERVER superglobal array.<br />// It contains the timestamp of the start of the request with microsecond precision.<br /></span><span style="color: #0000BB">$time </span><span style="color: #007700">= </span><span style="color: #0000BB">microtime</span><span style="color: #007700">(</span><span style="color: #0000BB">true</span><span style="color: #007700">) - </span><span style="color: #0000BB">$_SERVER</span><span style="color: #007700">[</span><span style="color: #DD0000">"REQUEST_TIME_FLOAT"</span><span style="color: #007700">];<br /><br />echo </span><span style="color: #DD0000">"Did nothing in </span><span style="color: #0000BB">$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>
</div>
<div class="refsect1 seealso" id="refsect1-function.microtime-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.time.html" class="function" rel="rdfs-seeAlso">time()</a> - Return current Unix timestamp</span></li>
</ul>
</p>
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