detachable command

foo.js

function command(cmd, shouldEnd, shouldDetach) { 
  var args    = cmd.trim().split(' ');
  var cmdName = args.shift();
  
  var opts  = shouldDetach ? {detached: true, stdio: ['ignore', out, err] } : {};
  var child = require('child_process').spawn(cmdName, args, opts);
 
  if (shouldDetach) {
    console.log('Spawned child ' + cmdName + ' with pid ' + child.pid);
    child.unref();
  } else {
    child.stdout.pipe(process.stdout, {end: shouldEnd});
    child.stderr.pipe(process.stderr, {end: shouldEnd});
  }
  
  return child;
}