A NodeJS script to find out free memory in Mac OSX. You can also find other data like total used memory, wired memory etc.

freeMemoryInMac.js

/**

 * User: Sohel
 * Date: 6/3/16
 * Time: 11:49 AM
 */

var sys = require('sys');
var exec = require('child_process').exec;
var child;
child = exec('vm_stat', function (error, stdout, stderr) {
  if (error === null && stderr === '') {
    //console.log(stdout);

    //remove . from the output
    stdout = stdout.replace(/\./g, '');

    //split it by new line
    var pieces = stdout.split('\n');

    var title = pieces.shift();
    //console.log(title);

    var memoryData = {};

    for(var i in pieces){
      var splittedMemoryString = pieces[i].split(':');
      memoryData[splittedMemoryString[0]] = ((splittedMemoryString[1]*4096)/1048576);  //in MB
    }

    //console.log(JSON.stringify(memoryData));
    //console.log(memoryData['Pages free'] , memoryData['Pages inactive']);
    var freeMemory = memoryData['Pages free'] + memoryData['Pages inactive'];
    console.log("Total Free Memory: ", freeMemory.toFixed(2), ' MB');
  }
});