计算PHP脚本运行时间

gistfile1.php

<?php   
function getmicrotime(){    
    list($usec, $sec) = explode(" ",microtime());    
    return ((float)$usec + (float)$sec);    
    }    
    
//例子   
    
//开始   
$time_start = getmicrotime();   
       
//这里放你的代码   
    
//结束   
$time_end = getmicrotime();   
$time = $time_end - $time_start;   
    
echo "Did nothing in $time seconds"; //输出运行总时间   
?>