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memory_get_usage

(PHP 4 >= 4.3.2, PHP 5)

memory_get_usageIndique la quantité de mémoire utilisée par PHP

Description

int memory_get_usage ([ bool $real_usage = false ] )

Retourne la quantité de mémoire allouée à PHP à cet instant.

Liste de paramètres

real_usage

Définir à TRUE pour récupérer la taille réelle de la mémoire allouée par le système. Si ce paramètre n'est pas défini ou vaut FALSE, seule la mémoire utilisée par emalloc() sera retournée.

Valeurs de retour

Retourne la quantité de mémoire, en octets.

Historique

Version Description
5.2.1 La compilation avec l'option de configuration --enable-memory-limit n'est plus nécessaire pour que cette fonction existe.
5.2.0 Le paramètre real_usage a été ajouté.

Exemples

Exemple #1 Exemple avec memory_get_usage()

<?php
// Ceci n'est qu'un exemple. Les chiffres ci-dessous
// différeront suivant les systèmes et les configurations

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

?>

Voir aussi

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User Contributed Notes 14 notes

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48
xelozz -at- gmail.com
4 years ago
To get the memory usage in KB or MB

<?php
function convert($size)
{
   
$unit=array('b','kb','mb','gb','tb','pb');
    return @
round($size/pow(1024,($i=floor(log($size,1024)))),2).' '.$unit[$i];
}

echo
convert(memory_get_usage(true)); // 123 kb
?>
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8
jeff dot peck at snet dot net
5 years ago
To get the memory usage in KB or MB

<?php
   
function echo_memory_usage() {
       
$mem_usage = memory_get_usage(true);
       
        if (
$mem_usage < 1024)
            echo
$mem_usage." bytes";
        elseif (
$mem_usage < 1048576)
            echo
round($mem_usage/1024,2)." kilobytes";
        else
            echo
round($mem_usage/1048576,2)." megabytes";
           
        echo
"<br/>";
    }
?>
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2
ad-rotator.com
10 years ago
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
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1
randolphothegreat at yahoo dot com
9 years ago
[EDIT by danbrown AT php DOT net: This is intended by the author to only be used with PHP 4 < 4.3.2.]

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:

<?php
$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.
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1
Alex Aulbach
3 years ago
Note, that the official IEC-prefix for kilobyte, megabyte and so on are KiB, MiB, TiB and so on.

See http://en.wikipedia.org/wiki/Tebibyte

At first glance this may sound like "What the hell? Everybody knows, that we mean 1024 not 1000 and the difference is not too big, so what?". But in about 10 years, the size of harddisks (and files on them) reaches the petabyte-limit and then the difference between PB and PiB is magnificent.

Better to get used to it now. :)
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0
lorin dot weilenmann at gmail dot com
3 years ago
I can confirm that this function triggers a garbage collection. I have a script that exceeded 128MB of memory at some point and ended with a fatal error. I was confused, because the script dealt with some large files initially, but the memory load from that point on should have been marginal, and the error occurred at the very end.

Those large files were dealt in a dedicated function and i even used unset() on the variable holding the file after the file was written to disk inside that function. So the memory should have been cleared twice, first after the unset() call, and second once the function ended.

To debug the memory usage, I called memory_get_usage(true) at some points and echo-ed the memory allocation. Just by adding a few echos here and there in the script, the memory usage never exceeded 1MB overhead (on top of the current file size) and the memory error disappeared.
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0
mario
4 years ago
not sure how this works internally but I have observed sort of side effects here: calling this function apparently triggers PHP's "garbage collector" -- and frees some memory. I managed to "fix" some savagely coded mess of a web application solely by calling this function just before the code that would usually throw out-of-memory errors. the php version there was 5.2.10
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0
miteigi nemoto (miteigi at yandex dot ru)
5 years ago
Decision a memory_get_usage problem for windows system

Tested OS: Windows XP
Server: Apache

PHP must be loaded as CGI to get correctly memory usage by Process ID ( getmypid() ) and with cmd-tools like tasklist.exe

PHP as CGI have your own PID instead constant Apache PID and you get a true memory size independed form Apache memory usage.

Configure in httpd.conf of Apache:

1. Comment the line like this:
LoadModule php4_module "/usr/local/php/sapi/php4apache.dll"
or
LoadModule php5_module "/usr/local/php5/php5apache.dll"

2. Add this and edit your path to php:
<Directory "z:/usr/local/php">
  Options ExecCGI
</Directory>
ScriptAlias "/__php_dir__/" "z:/usr/local/php/"
Action application/x-httpd-php "/__php_dir__/php.exe"

3. Restart Apache

Use this PHP-code:

<?php
/**
* A memory_get_usage() for Windows System, wich compiled without --enable-memory-limit
* PHP must be loaded as CGI
* Greetings form miteigi nemoto
* @return string
*/
function memory_get_usage_by_tasklist()
{
   
$output = array();
   
exec( 'tasklist ', $output );
    foreach (
$output as $value)
    {
       
$ex=explode(" ",$value);
       
$count_ex=count($ex);
        if (
eregi(" ".getmypid()." Console",$value))
        {
           
$memory_size=$ex[$count_ex-2]." Kb";
            return
$memory_size;
        }
    }
}
echo
memory_get_usage_by_tasklist();
?>
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1
vesa dot kivisto at nepton dot fi
9 years ago
[EDIT by danbrown AT php DOT net: This function will only extend Windows versions of PHP where the server has the required third-party software.]

I was unable to get the previous examples working properly and created code which works at least for me. Enjoy!

<?php
// 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>';
 
}
?>
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0
grey - greywyvern - com
9 years ago
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.
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0
guenter_doege at web dot de
9 years ago
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>';
       }
}
?>
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0
MagicalTux at FF dot st
9 years ago
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")
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-2
joe at schmoe dot com
7 years ago
the various memory_get_usage replacements here don't seem to work on Mac OS X 10.4(Intel)

I got it to work like this...

<?php
function memory_get_usage()
{
    
$pid = getmypid();
    
exec("ps -o rss -p $pid", $output);
     return
$output[1] *1024;
}
?>
up
-1
e dot a dot schultz at gmail dot com
8 years ago
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;
        }
    }
}
?>
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