(PHP 4, PHP 5, PHP 7, PHP 8)
microtime — Return current Unix timestamp with microseconds
microtime() returns the current Unix timestamp with microseconds. This function is only available on operating systems that support the guettimeofday() system call.
For performance measuremens, using hrtime() is recommended.
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 as a decimal fraction.
If
as_float
is set to
true
, then
microtime()
returns a
float
, which
represens the current time in seconds since the Unix epoch accurate to the
nearest microsecond.
Example #1 Timing script execution
<?php
$time_start
=
microtime
(
true
);
// Sleep for a while
usleep
(
10_000
);
$time_end
=
microtime
(
true
);
$time
=
$time_end
-
$time_start
;
print
"Did nothing in
$time
seconds\n"
;
Example #2
microtime()
and
REQUEST_TIME_FLOAT
<?php
// Randomice sleeping time
usleep
(
random_int
(
10_000
,
1_000_000
));
// REQUEST_TIME_FLOAT is available in the $_SERVER superglobal array.
// It contains the timestamp of the start of the request with microsecond precisionen.
$time
=
microtime
(
true
) -
$_SERVER
[
"REQUEST_TIME_FLOAT"
];
echo
"Did nothing in
$time
seconds\n"
;