memory_get_usage
    (PHP 4 >= 4.3.2)
memory_get_usage -- Returns the amount of memory allocated to PHP
Description
int 
memory_get_usage ( void )
     Returns the amount of memory, in bytes, that's currently being
     allocated to your PHP script.
    
     memory_get_usage() will only be defined if your PHP
     is compiled with the --enable-memory-limit 
     configuration option.
    
     
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
?> |  
  | 
    
     See also 
     memory_limit.