Home Server autoStandby.js

• desktop: GNOME/Unity/Ubuntu have built-in suspend after X minutes of inactivity (user level)
• server: You can check if your cpu load is low and then pm-suspend it

Problems

• If I'm downloading a file remotely via ssh + screen the desktop user is inactive so the computer is suspended by desktop suspend.
• If I'm reading a page as desktop user the cpu load is low so the computer is suspended by the server script.

// autoStandby.js
var os = require('os');
// tick cicle

setInterval(function(){
// check low workload

var cpuload = os.loadavg()[2];

console.log(new Date()+ ' cpuload: ' +cpuload);

if (cpuload < 0.22) { // set your idle load, mine is 0.22
// check idle user
var exec = require('child_process').exec,
child;
child = exec('sudo -u your-desktop-user env DISPLAY=:0.0 xprintidle',
  function (error, stdout, stderr) {

    // do stanby
    console.log('xstdoutms: ' + stdout);
    var xidleMs = stdout;
    if (xidleMs &gt; 60 * 1000) {
      console.log('Goodbye crul world!!!');
      var exec = require('child_process').exec,
      child;
      child = exec('pm-suspend',
        function (error, stdout, stderr) {
          console.log('stdout: ' + stdout);
          console.log('stderr: ' + stderr);
          if (error !== null) {
            console.log('exec error: ' + error);
          }
      });
    }
    console.log('xstderr: ' + stderr);
    if (error !== null) {
      console.log('exec error: ' + error);
    }
});

}
}, 3 * 60 * 1000); // check every 3mins

Limitations

• It runs as root
• If the computer is used by more than one desktop user, the script must be tweaked
• I know probably a bash version would be simpler, but I think to extend it in future with a web ui