sysinfo.js, get system information in json format.

sysinfo.js

/**
 * Get System Information in json format. Gets Run Queue, Memory and Swap Info.
 */

var os = require('os');
var fs = require('fs');

var sysinfo = {};

sysinfo.hostname = os.hostname();

sysinfo.os = {};
sysinfo.os.release          = os.release();
sysinfo.os.platform         = os.platform();
sysinfo.os.arch             = os.arch();

sysinfo.cpu = {};
sysinfo.cpu.run_queue_1     = os.loadavg()[0].toFixed(2);
sysinfo.cpu.run_queue_5     = os.loadavg()[1].toFixed(2);
sysinfo.cpu.run_queue_15    = os.loadavg()[2].toFixed(2);

sysinfo.memory = {};
sysinfo.memory.total        = os.totalmem();
sysinfo.memory.free         = os.freemem();
sysinfo.memory.used_perc    = (100 - ( ( os.totalmem() - os.freemem() ) / os.totalmem() * 100) ) .toFixed(2);

/**
 * Gets Swap info out of /proc/swaps on Linux systems.
 */
function getSwap() {
    var swapinfo = [];
    
    fs.readFileSync('/proc/swaps').toString().split(os.EOL).forEach(function(line) {
       var lineArray = line.split(/\s+/);
       if ( lineArray[0] != 'Filename' ) {
           var tempObject = {};
           tempObject.size = parseInt(lineArray[2]);
           tempObject.used = parseInt(lineArray[3]);
           tempObject.perc = ( tempObject.used / tempObject.size * 100).toFixed(2);
           if ( ! isNaN(tempObject.size) ) {
            swapinfo.push(tempObject);    
           }
       } 
    });
    
    return swapinfo;
};

sysinfo.swap = getSwap();

console.log(sysinfo);

Seems like the memory used_perc is actually the free %