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.
  
Parameters
   
- get_as_float
 
       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.
      
       If the optional get_as_float is set to
       TRUE then a float (in seconds) is returned.
      
 
  Examples
   
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"; ?>
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   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"; ?>
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