A test snipped of launching sails using spawn, then killing it and waiting for the 'exit event.

spawn-sails.js

var spawn = require('child_process').spawn;
var wrench = require('wrench');
var sailsBin = './node_modules/sails/bin/sails.js';

var _kill = function(sailsServer, cb) {
  sailsServer.on('exit', function(code, signal){
    cb();
  });
  sailsServer.kill('SIGINT');
};

var _spawn = function(cb) {
  // clean out the database directories
  wrench.rmdirSyncRecursive('./.tmp', true);
  var sailsServer = spawn(sailsBin, ['lift']);
  var lifted = false;
  var dataString = '';
  sailsServer.stdout.on('data', function(data) {
    if (lifted) { return; }
    dataString = dataString + data;
    // If the server lifted, it passed
    if (dataString.indexOf('Server lifted') !== -1) {
      lifted = true;
      return cb(sailsServer, dataString);
    }
    // Otherwise check for an error message
    if (dataString.toLowerCase().indexOf('error') !== -1) {
      lifted = true;
      kill(sailsServer, function() {
        return cb(null, dataString);          
      });
    }
  });
};

_spawn(function (sailsServer, data) {
  console.log('Sails launched');
  console.log(data);
  _kill(sailsServer, function() {
    console.log('Process finished.');
  });
});