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microtime

(PHP 4, PHP 5)

microtimeReturn current Unix timestamp with microseconds

Description

mixed microtime ([ bool $get_as_float = false ] )

microtime() returns the current Unix timestamp with microseconds. This function is only available on operating systems that support the gettimeofday() system call.

Parameters

get_as_float

If used and set to TRUE, microtime() will return a float instead of a string, as described in the return values section below.

Return Values

By default, microtime() returns a string in the form "msec sec", where sec is the number of seconds since the Unix epoch (0:00:00 January 1,1970 GMT), and msec measures microseconds that have elapsed since sec and is also expressed in seconds.

If get_as_float is set to TRUE, then microtime() returns a float, which represents the current time in seconds since the Unix epoch accurate to the nearest microsecond.

Changelog

Version Description
5.0.0 The get_as_float parameter was added.

Examples

Example #1 Timing script execution with microtime()

<?php
/**
 * Simple function to replicate PHP 5 behaviour
 */
function microtime_float()
{
    list(
$usec$sec) = explode(" "microtime());
    return ((float)
$usec + (float)$sec);
}

$time_start microtime_float();

// Sleep for a while
usleep(100);

$time_end microtime_float();
$time $time_end $time_start;

echo 
"Did nothing in $time seconds\n";
?>

Example #2 Timing script execution in PHP 5

<?php
$time_start 
microtime(true);

// Sleep for a while
usleep(100);

$time_end microtime(true);
$time $time_end $time_start;

echo 
"Did nothing in $time seconds\n";
?>

Example #3 microtime() and REQUEST_TIME_FLOAT (as of PHP 5.4.0)

<?php
// Randomize sleeping time
usleep(mt_rand(10010000));

// As of PHP 5.4.0, REQUEST_TIME_FLOAT is available in the $_SERVER superglobal array.
// It contains the timestamp of the start of the request with microsecond precision.
$time microtime(true) - $_SERVER["REQUEST_TIME_FLOAT"];

echo 
"Did nothing in $time seconds\n";
?>

See Also

  • time() - Return current Unix timestamp

PHP Manual