reference/datetime/functions/microtime.xml
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<refsect1 role="description">
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&reftitle.description;
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<methodsynopsis>
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<type>mixed</type><methodname>microtime</methodname>
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<methodparam choice="opt"><type>bool</type><parameter>get_as_float</parameter><initializer>false</initializer></methodparam>
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<type class="union"><type>string</type><type>float</type></type><methodname>microtime</methodname>
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<methodparam choice="opt"><type>bool</type><parameter>as_float</parameter><initializer>&false;</initializer></methodparam>
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</methodsynopsis>
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<para>
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<function>microtime</function> returns the current Unix timestamp with
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microseconds. This function is only available on operating systems that
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support the gettimeofday() system call.
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</para>
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<para>
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For performance measurements, using <function>hrtime</function> is recommended.
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</para>
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</refsect1>
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<refsect1 role="parameters">
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<para>
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<variablelist>
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<varlistentry>
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<term><parameter>get_as_float</parameter></term>
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<term><parameter>as_float</parameter></term>
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<listitem>
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<para>
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If used and set to &true;, <function>microtime</function> will return a
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the form "msec sec", where <literal>sec</literal> is the number of seconds
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since the Unix epoch (0:00:00 January 1,1970 GMT), and <literal>msec</literal>
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measures microseconds that have elapsed since <literal>sec</literal>
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and is also expressed in seconds.
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and is also expressed in seconds as a decimal fraction.
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</para>
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<para>
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If <parameter>get_as_float</parameter> is set to &true;, then
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If <parameter>as_float</parameter> is set to &true;, then
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<function>microtime</function> returns a <type>float</type>, which
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represents the current time in seconds since the Unix epoch accurate to the
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nearest microsecond.
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&reftitle.examples;
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<para>
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<example>
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<title>Timing script execution with <function>microtime</function></title>
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<programlisting role="php">
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<![CDATA[
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<?php
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/**
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* Simple function to replicate PHP 5 behaviour
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*/
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function microtime_float()
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{
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list($usec, $sec) = explode(" ", microtime());
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return ((float)$usec + (float)$sec);
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}
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$time_start = microtime_float();
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// Sleep for a while
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usleep(100);
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$time_end = microtime_float();
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$time = $time_end - $time_start;
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echo "Did nothing in $time seconds\n";
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?>
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]]>
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</programlisting>
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</example>
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<example>
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<title>Timing script execution in PHP 5</title>
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<title>Timing script execution</title>
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<programlisting role="php">
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<![CDATA[
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<?php
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</programlisting>
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</example>
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<example>
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<title><function>microtime</function> and <literal>REQUEST_TIME_FLOAT</literal> (as of PHP 5.4.0)</title>
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<title><function>microtime</function> and <literal>REQUEST_TIME_FLOAT</literal></title>
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<programlisting role="php">
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<![CDATA[
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<?php
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// Randomize sleeping time
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usleep(mt_rand(100, 10000));
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// As of PHP 5.4.0, REQUEST_TIME_FLOAT is available in the $_SERVER superglobal array.
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// REQUEST_TIME_FLOAT is available in the $_SERVER superglobal array.
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// It contains the timestamp of the start of the request with microsecond precision.
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$time = microtime(true) - $_SERVER["REQUEST_TIME_FLOAT"];
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<para>
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<simplelist>
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<member><function>time</function></member>
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<member><function>hrtime</function></member>
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</simplelist>
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</para>
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</refsect1>
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</refentry>
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<!-- Keep this comment at the end of the file
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Local variables:
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mode: sgml
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