microtime
    (PHP 3, PHP 4 , PHP 5)
microtime -- 
     Return current Unix timestamp with microseconds
    
Description
mixed 
microtime ( [bool get_as_float])
     microtime() returns the current Unix timestamp with
     microseconds. This function is only available on operating systems that
     support the gettimeofday() system call.
    
     When called without the optional argument, this function returns the string
     "msec sec" where sec is the current time measured in the number of
     seconds since the Unix Epoch (0:00:00 January 1, 1970 GMT), and 
     msec is the microseconds part. 
     Both portions of the string are returned in units of seconds.
    
     When get_as_float is given, and evaluates to 
     TRUE, microtime() will return a float.
    
Note: 
      The get_as_float parameter was added as of
      PHP 5.0.0.
     
     
Example 1. Timing script execution with microtime() 
<?php /**  * Simple function to replicate PHP 5 behaviour  */ function microtime_float()  {      list($usec, $sec) = explode(" ", microtime());      return ((float)$usec + (float)$sec);  } 
  $time_start = microtime_float();
  // Sleep for a while usleep(100);
  $time_end = microtime_float(); $time = $time_end - $time_start;
  echo "Did nothing in $time seconds\n"; ?>
 |  
  | 
     Example 2. Timing script execution in PHP 5 
<?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"; ?>
 |  
  | 
    
     See also time().