(PHP 4 >= 4.3.2, PHP 5)
memory_get_usage — Returns the amount of memory allocated to PHP
$real_usage = false
  ] )Returns the amount of memory, in bytes, that's currently being allocated to your PHP script.
real_usage
       Set this to TRUE to get the real size of memory allocated from
       system. If not set or FALSE only the memory used by
       emalloc() is reported.
      
Returns the memory amount in bytes.
| Version | Description | 
|---|---|
| 5.2.1 | Compiling with --enable-memory-limit is no longer required for this function to exist. | 
| 5.2.0 | real_usagewas added. | 
Example #1 A memory_get_usage() example
<?php
// This is only an example, the numbers below will
// differ depending on your system
echo memory_get_usage() . "\n"; // 36640
$a = str_repeat("Hello", 4242);
echo memory_get_usage() . "\n"; // 57960
unset($a);
echo memory_get_usage() . "\n"; // 36744
?>