memory_get_usage

(PHP 4 >= 4.3.2, PHP 5)

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.

例子 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.


add a note add a note User Contributed Notes
e dot a dot schultz at gmail dot com
09-Apr-2006 07:41
This is a function that should work for both Windows XP/2003 and most distrabutions of UNIX and Mac OS X.

<?php
if( !function_exists('memory_get_usage') )
{
   function
memory_get_usage()
   {
      
//If its Windows
       //Tested on Win XP Pro SP2. Should work on Win 2003 Server too
       //Doesn't work for 2000
       //If you need it to work for 2000 look at http://us2.php.net/manual/en/function.memory-get-usage.php#54642
      
if ( substr(PHP_OS,0,3) == 'WIN')
       {
               if (
substr( PHP_OS, 0, 3 ) == 'WIN' ):
              
$output = array();
              
exec( 'tasklist /FI "PID eq ' . getmypid() . '" /FO LIST', $output );
      
               return
preg_replace( '/[\D]/', '', $output[5] ) * 1024;           
       }else
       {
          
//We now assume the OS is UNIX
           //Tested on Mac OS X 10.4.6 and Linux Red Hat Enterprise 4
           //This should work on most UNIX systems
          
$pid = getmypid();
          
exec("ps -eo%mem,rss,pid | grep $pid", $output);
          
$output = explode("  ", $output[0]);
          
//rss is given in 1024 byte units
          
return $output[1] * 1024;
       }
   }
}
?>
xolox at home dot nl
03-Apr-2006 09:02
<?php

// Original from http://php.net/memory_get_usage by websjwans at hotmail dot com. Thanks alot!
if ( ! function_exists( 'memory_get_usage' ) ):
  
// Only define function if it doesn't exist
  
function memory_get_usage()
   {
      
// If we are running on Windows
      
if ( substr( PHP_OS, 0, 3 ) == 'WIN' ):
          
$output = array();
          
// Should check whether tasklist is available, but I'm lazy
          
exec( 'tasklist /FI "PID eq ' . getmypid() . '" /FO LIST', $output );
          
// Filter non-numeric characters from output. Why not use substr & strpos?
           // I'm running Windows XP Pro Dutch, and it's output does not match the
           // English variant, as will all other translations. This is a more generic
           // approach, and has a better chance of actually working
          
return preg_replace( '/[^0-9]/', '', $output[5] ) * 1024;
          
// Tasklist outputs memory usage in kilobytes, memory_get_usage in bytes.
           // So we multiply by 1024 and in the process convert from string to integer.
      
else:
           return
false;
       endif;
   }
endif;

?>

Works for me. Functionality should match memory_get_usage(), albeit slower (exec & regex). Have fun!

- Peter Odding
John Ring
22-Mar-2006 03:54
Oops, that was a question.

I'll change it to a note simply:

Note: This is NOT enabled at all in the Win32 builds.

Best regards
grey - greywyvern - com
18-Aug-2005 03:37
If nothing else in the user notes below works for you, you can get a very (VERY) rough estimate of PHP memory usage by outputting the $GLOBALS array, stripping it of indentation whitespace, and counting the characters in the resulting string.  This method has a very high overhead (to be expected), but works on all operating systems, regardless of whether or not they have the --enable-memory-limit config option set.  I find that the syntax overhead of the print_r() statement roughly accounts for the PHP runtime base memory usage.

The code below is set up to work on all arrays, not just the $GLOBALS array.  Keep in mind that outside data referenced by resource IDs, such as database results and open file data, is not included in this total.

<?php

function array_size($arr) {
 
ob_start();
 
print_r($arr);
 
$mem = ob_get_contents();
 
ob_end_clean();
 
$mem = preg_replace("/\n +/", "", $mem);
 
$mem = strlen($mem);
  return
$mem;
}

$memEstimate = array_size($GLOBALS);

?>

Use only if being off to either side by at least 20% is acceptible for your purposes.
vesa dot kivisto at nepton dot fi
14-Jul-2005 09:02
I was unable to get the previous examples working properly and created code which works at least for me. Enjoy!

// Please note that you'll need the pslist.exe utility from http://www.sysinternals.com/Utilities/PsTools.html
// This is because win/2000 itself does not provide a task list utility.
//
function getMemoryUsage() {

 // try to use PHP build in function
 if( function_exists('memory_get_usage') ) {
  return memory_get_usage();
 }

 // Try to get Windows memory usage via pslist command
 if ( substr(PHP_OS,0,3) == 'WIN') {
 
  $resultRow = 8;
  $resultRowItemStartPosition = 34;
  $resultRowItemLength = 8;
 
  $output = array();
  exec('pslist -m ' . getmypid() , $output);
  
  return trim(substr($output[$resultRow], $resultRowItemStartPosition, $resultRowItemLength)) . ' KB';
 
 }

 
 // No memory functionality available at all
 return '<b style="color: red;">no value</b>';
 
}
guenter_doege at web dot de
11-Jul-2005 02:28
The Win XP / 2003 workaround script will also work with windows 2000 with a few slight modifications.

Please note that you'll need the pslist.exe utility from http://www.sysinternals.com/Utilities/PsTools.html because win/2000 itself does not provide a task list utility.

<?php

function getMemUsage()
{
    
       if (
function_exists('memory_get_usage'))
       {
           return
memory_get_usage();
       }
       else if (
substr(PHP_OS,0,3) == 'WIN')
       {
          
// Windows 2000 workaround

          
$output = array();
          
exec('pslist ' . getmypid() , $output);
           return
trim(substr($output[8],38,10));
       }
       else
       {
           return
'<b style="color: red;">no value</b>';
       }
}
?>
MagicalTux at FF dot st
25-May-2005 03:08
When you need to get the OS, do not use $_SERVER['OS'] or $_ENV['OS'], better use PHP_OS constant !
<?php
if (substr(PHP_OS,0,3)=='WIN') {
 
// [...]
}
?>

You also have other values such as CYGWIN_NT-5.0, Linux, ... this is the best way to get system's os (anyone on linux can do an "export OS=windows")
webNOSPAMsjwans at hotmail dot com
01-Dec-2004 11:09
A quick and dirty Windows XP / 2003 wordaround:

<?php

function getMemUsage()
{
      
       if (
function_exists('memory_get_usage'))
       {
           return
memory_get_usage();
       }
       else if (
strpos( strtolower($_SERVER["OS"]), 'windows') !== false)
       {
          
// Windows workaround
          
$output = array();
          
          
exec('tasklist /FI "PID eq ' . getmypid() . '" /FO LIST', $output);           
           return
substr($output[5], strpos($output[5], ':') + 1);
       }
       else
       {
           return
'<b style="color: red;">no value</b>';
       }
}

?>
randolphothegreat at yahoo dot com
30-Nov-2004 05:37
I'd just like to point out that although sandeepc at myrealbox dot com's idea for displaying the current memory usage is a good one, it's perhaps a bad idea to pipe the entire process list through grep. A better performing method would be to select only the process we're interested in:

<?
$pid
= getmypid();
error_log('MEMORY USAGE (% KB PID ): ' . `ps --pid $pid --no-headers -o%mem,rss,pid`);
?>

True, it's not much of a performance boost, but every bit helps.
ad-rotator.com
15-May-2004 01:31
The method sandeepc at myrealbox dot com posted yields larger memory usage, my guess is that it includes all the PHP interpreter/internal code and not just the script being run.

1) Use ps command
MEMORY USAGE (% KB PID ):  0.8 12588 25087 -> about 12MB
2) Use memory_get_usage()
int(6041952) -> about 6MB
sandeepc at myrealbox dot com
12-Nov-2003 01:15
To get this in pre 4.2.3 do a (works on unix like systems only):

$my_pid = getmypid();
error_log("MEMORY USAGE (% KB PID ): ".`ps -eo%mem,rss,pid | grep $my_pid`);

found this tip somewhere in bugs.php.net!