PHP get exact time a particular line is executed

I'm trying to perform a simple benchmark on a script I have. First I tried to just add something like:

echo 'After Checklist: '. date('h:i:s:u A') ."<br />";

but it just prints out the same time for a lot of the times - it isn't until a includes script is ran that 开发者_JAVA技巧it returns a different time. Is there anyway to do this? Or something similar - I basically just want to see where the bottleneck is so I can increase performance.

You want to use the microtime function which will return the current Unix timestamp with microseconds.

From here you can do simple subtraction from the start and end time to get the desired results. The trick however, is to pass in "true" into the function so it returns a float value, rather than a string.

An example, as posted on php.net is this:

<?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";
?>

I think you need microtime: http://php.net/manual/en/function.microtime.php