How to use the portage.os.EX_OK function in portage

def _async_start(self):

		if not self._force_async:
			try:
				self._imp = lockfile(self.path,
					wantnewlockfile=True, flags=os.O_NONBLOCK)
			except TryAgain:
				pass
			else:
				self.returncode = os.EX_OK
				self._async_wait()
				return

		if self._force_process or \
			(not self._force_thread and \
			(self._use_process_by_default or threading is dummy_threading)):
			self._imp = _LockProcess(path=self.path, scheduler=self.scheduler)
		else:
			self._imp = _LockThread(path=self.path,
				scheduler=self.scheduler,
				_force_dummy=self._force_dummy)

		self._imp.addExitListener(self._imp_exit)
		yield self._imp.async_start()

logging.info("dry-run: copy '%s' from %s to distfiles" %
						(self.distfile, current_mirror.name))
				self._success()
				self.returncode = os.EX_OK
				self.wait()
				return
			else:
				src = os.path.join(current_mirror.location, self.distfile)
				dest = os.path.join(self.config.options.distfiles,
						self.config.layouts[0].get_path(self.distfile))
				if self._hardlink_atomic(src, dest,
					"%s to %s" % (current_mirror.name, "distfiles")):
					logging.debug("hardlink '%s' from %s to distfiles" %
						(self.distfile, current_mirror.name))
					self._success()
					self.returncode = os.EX_OK
					self.wait()
					return
				else:
					self._start_task(
						FileCopier(src_path=src, dest_path=dest,
							background=(self.background and
								self._log_path is not None),
							logfile=self._log_path),
						self._fs_mirror_copier_exit)
					return

		self._try_next_mirror()

def _merge_exit(self, merge_task):
		if self._final_exit(merge_task) != os.EX_OK:
			self._start_exit_hook(self.returncode)
			return

		self.postinst_failure = merge_task.postinst_failure
		pkg = self.pkg
		self.world_atom(pkg)
		pkg_count = self.pkg_count
		pkg_path = self.pkg_path
		logger = self.logger
		if "noclean" not in self.settings.features:
			short_msg = "emerge: (%s of %s) %s Clean Post" % \
				(pkg_count.curval, pkg_count.maxval, pkg.cpv)
			logger.log((" === (%s of %s) " + \
				"Post-Build Cleaning (%s::%s)") % \
				(pkg_count.curval, pkg_count.maxval, pkg.cpv, pkg_path),
				short_msg=short_msg)

def emirrordist_main(args):

	# The calling environment is ignored, so the program is
	# completely controlled by commandline arguments.
	env = {}

	if not sys.stdout.isatty():
		portage.output.nocolor()
		env['NOCOLOR'] = 'true'

	parser, options, args = parse_args(args)

	if options.version:
		sys.stdout.write("Portage %s\n" % portage.VERSION)
		return os.EX_OK

	config_root = options.config_root

	if options.repositories_configuration is not None:
		env['PORTAGE_REPOSITORIES'] = options.repositories_configuration

	settings = portage.config(config_root=config_root,
		local_config=False, env=env)

	default_opts = None
	if not options.ignore_default_opts:
		default_opts = settings.get('EMIRRORDIST_DEFAULT_OPTS', '').split()

	if default_opts:
		parser, options, args = parse_args(default_opts + args)

def _task_exit(self, task):
		self._running_tasks.discard(task)
		if task.returncode != os.EX_OK:
			self._error_count += 1
		self._schedule()

def _extractor_exit(self, extractor_proc):

		if self._default_exit(extractor_proc) != os.EX_OK:
			self._remove_dest_env()
			self.wait()
			return

		# This is a signal to ebuild.sh, so that it knows to filter
		# out things like SANDBOX_{DENY,PREDICT,READ,WRITE} that
		# would be preserved between normal phases.
		open(_unicode_encode(self._get_dest_env_path() + '.raw'), 'wb').close()

		self._current_task = None
		self.returncode = os.EX_OK
		self.wait()

is_pty is True if a pty was successfully allocated, and
		False if a normal pipe was allocated.
	"""

	got_pty = False

	global _disable_openpty, _fbsd_test_pty

	if _fbsd_test_pty and not _disable_openpty:
		# Test for python openpty breakage after freebsd7 to freebsd8
		# upgrade, which results in a 'Function not implemented' error
		# and the process being killed.
		pid = os.fork()
		if pid == 0:
			pty.openpty()
			os._exit(os.EX_OK)
		pid, status = os.waitpid(pid, 0)
		if (status & 0xff) == 140:
			_disable_openpty = True
		_fbsd_test_pty = False

	if _disable_openpty:
		master_fd, slave_fd = os.pipe()
	else:
		try:
			master_fd, slave_fd = pty.openpty()
			got_pty = True
		except EnvironmentError as e:
			_disable_openpty = True
			writemsg("openpty failed: '%s'\n" % str(e),
				noiselevel=-1)
			del e

def perform_post_sync_hook(self, reponame, dosyncuri='', repolocation=''):
		succeeded = os.EX_OK
		if reponame:
			_hooks = self.hooks["repo.postsync.d"]
		else:
			_hooks = self.hooks["postsync.d"]
		for filepath in _hooks:
			writemsg_level("Spawning post_sync hook: %s\n"
				% (_unicode_decode(_hooks[filepath])),
				level=logging.ERROR, noiselevel=4)
			if reponame:
				retval = portage.process.spawn(
					[filepath, reponame, dosyncuri, repolocation],
					env=self.settings.environ())
			else:
				retval = portage.process.spawn([filepath],
					env=self.settings.environ())
			if retval != os.EX_OK:

def profile_check(trees, myaction):
	if myaction in ("help", "info", "search", "sync", "version"):
		return os.EX_OK
	for root_trees in trees.values():
		if (root_trees["root_config"].settings.profiles and
			'ARCH' in root_trees["root_config"].settings):
			continue
		# generate some profile related warning messages
		validate_ebuild_environment(trees)
		msg = ("Your current profile is invalid. If you have just changed "
			"your profile configuration, you should revert back to the "
			"previous configuration. Allowed actions are limited to "
			"--help, --info, --search, --sync, and --version.")
		writemsg_level("".join("!!! %s\n" % l for l in textwrap.wrap(msg, 70)),
			level=logging.ERROR, noiselevel=-1)
		return 1
	return os.EX_OK

prompt = "Would you like to remove these " + \
					"packages from your world favorites?"
				uq = UserQuery(opts)
				if uq.query(prompt, enter_invalid) == 'No':
					return 128 + signal.SIGINT

			remaining = set(world_set)
			remaining.difference_update(discard_atoms)
			if not pretend:
				world_set.replace(remaining)
		else:
			print(">>> No matching atoms found in \"world\" favorites file...")
	finally:
		if locked:
			world_set.unlock()
	return os.EX_OK