get server ram with php

Question

Is there a way to know the avaliable ram in a server (linux distro) with php (widthout using linux commands)?

edit: sorry, the objective is to be aware of the ram available in the server / virtual machine, for the particular server (even if that memory is shared).

Answer 1

If you know this code will only be running under Linux, you can use the special /proc/meminfo file to get information about the system's virtual memory subsystem. The file has a form like this:

MemTotal:       255908 kB
MemFree:         69936 kB
Buffers:         15812 kB
Cached:         115124 kB
SwapCached:          0 kB
Active:          92700 kB
Inactive:        63792 kB
...

That first line, MemTotal: ..., contains the amount of physical RAM in the machine, minus the space reserved by the kernel for its own use. It's the best way I know of to get a simple report of the usable memory on a Linux system. You should be able to extract it via something like the following code:

<?php
  $fh = fopen('/proc/meminfo','r');
  $mem = 0;
  while ($line = fgets($fh)) {
    $pieces = array();
    if (preg_match('/^MemTotal:\s+(\d+)\skB$/', $line, $pieces)) {
      $mem = $pieces[1];
      break;
    }
  }
  fclose($fh);

  echo "$mem kB RAM found"; ?>

(Please note: this code may require some tweaking for your environment.)