PHP Manual: microtime

PHP Manual
Prev		Next

microtime

(PHP 3, PHP 4, PHP 5)

microtime -- Return current Unix timestamp with microseconds

Description

mixed microtime ( [bool get_as_float] )

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

When called without the optional argument, this function returns the string "msec sec" where sec is the current time measured in the number of seconds since the Unix Epoch (0:00:00 January 1, 1970 GMT), and msec is the microseconds part. Both portions of the string are returned in units of seconds.

If the optional get_as_float is set to TRUE then a float (in seconds) is returned.

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";
?>