A node.js based gnome desktop background interval switcher.

switcher.js

#!/usr/local/bin/node
(function() {
  "use strict";

  // The purpose of this script is to switch the gnome background every x
  // minutes.
  
  var exec = require('child_process').exec
    , fs = require('fs')
    , interval = 0
    , imgDir = ''
    , loop
    ;
  
  function usage() {
    console.log("./switcher.js <interval in minutes> <full path to images directory>\n  Example: ./switcher.js 15 /home/eric/Pictures/wallpaper_general/");
  }

  function init() {
    if(process.argv.length != 4) {
      console.log('argv length:', process.argv.length);
      usage();
      process.exit(1);
    }

    interval = parseInt(process.argv[2]);
    imgDir = process.argv[3];
    selectRandom();
    loop = setInterval(selectRandom, (interval * 1000)*60);

  }

  function selectRandom() {
    fs.readdir(imgDir, function(err, files) {
      display(files[parseInt(Math.random() * files.length - 1)]);
    });
  }

  function display(file) {
    exec('/usr/bin/gsettings set org.gnome.desktop.background picture-uri file://' + imgDir + '/' + file, function (err, stdout, stderr) {
      if(err) {
        console.error('Error: ', err);
      }
    });
  }

  init();

}());