How to get time in PHP with nanosecond precision?
Is this even possible in P开发者_StackOverflow社区HP?
If not, what is the highest precision available?
The microtime
function is what you're looking for.
PHP does not supply a function that has higher precision than microseconds.
You can use the system
function to get the value straight from the machine if you are running Linux:
$nanotime = system('date +%s%N');
%s
is the amount of seconds, appended by %N
, which is the amount of nanoseconds.
Now with this extension it's nanosecond timing is possible http://pecl.php.net/hrtime . Yet it is a stopwatch class implemented to suite the highest possible resolution on different platforms.
As of PHP 7.3 there's also a crossplatform hrtime()
function in the core http://php.net/manual/en/function.hrtime.php.
microtime() is the highest precision using PHP's vocabulary. You can also make a system call by using Unix date
and specify %N
format if you need nanosecond accuracy. Unix ntp_gettime()
has even higher resolution and returns jitter/wander/stability/shift/calibration data.
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