register_shutdown_function.php

<?php
// capture the start time
$start_time = microtime(true);
 
// do some stuff
// ...
 
// display how long the script took
echo "execution took: ".
        (microtime(true) - $start_time).
        " seconds.";

/// ---------------------------------------------------

$start_time = microtime(true);
 
register_shutdown_function('my_shutdown');
 
// do some stuff
// ...
 
 
function my_shutdown() {
    global $start_time;
 
    echo "execution took: ".
            (microtime(true) - $start_time).
            " seconds.";
}