code: function isRunning(pid, callback) {
  	var command;
  	if(!pid) {
  		callback(false);
  		return;
  	}
  	command = 'ps -ef | grep \'' + nodejs + '\'| grep \'' + serverName + '\' | grep -v grep | awk \'{print $2}\'';
  	exec(command, function(err, stdout, stderr) {
  		var pids;
  		if(err || stderr) {
  			callback(false);
  			return;
  		}
  		pids = stdout.trim().split("\n");
  		if(pids.indexOf(pid) != -1) {
  			callback(true);
  			return;
  		}
  		callback(false);
  	});
  }
docs: No guarantee