@homebridge/dbus-native/lib/address-x11.js

D-bus protocol implementation in native javascript

// read dbus address from X11 window selection
// Requires the optional `x11` peer dependency.

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

function getDbusAddress(callback) {
  var x11;
  try {
    x11 = require('x11');
  } catch (e) {
    return callback(
      new Error(
        "address-x11 requires the optional 'x11' package; install it with `npm install x11`"
      )
    );
  }
  // read machine uuid
  fs.readFile('/var/lib/dbus/machine-id', 'ascii', function (err, uuid) {
    if (err) return callback(err);
    var hostname = os.hostname().split('-')[0];
    x11.createClient(function (err, display) {
      var X = display.client;
      var selectionName = `_DBUS_SESSION_BUS_SELECTION_${hostname}_${uuid.trim()}`;
      X.InternAtom(false, selectionName, function (err, id) {
        if (err) return callback(err);
        X.GetSelectionOwner(id, function (err, win) {
          if (err) return callback(err);
          X.InternAtom(
            false,
            '_DBUS_SESSION_BUS_ADDRESS',
            function (err, propId) {
              if (err) return callback(err);
              win = display.screen[0].root;
              X.GetProperty(
                0,
                win,
                propId,
                0,
                0,
                10000000,
                function (err, val) {
                  if (err) return callback(err);
                  callback(null, val.data.toString());
                }
              );
            }
          );
        });
      });
    });
  });
}

module.exports = getDbusAddress;