Python os.open函数代码示例

		def make_pipes():
			tempdir = tempfile.mkdtemp()
			fifo_path = os.path.join(tempdir, 'fifo')
			os.mkfifo(fifo_path)
			return ((os.open(fifo_path, os.O_NONBLOCK|os.O_RDONLY),
				os.open(fifo_path, os.O_NONBLOCK|os.O_WRONLY)),
				functools.partial(shutil.rmtree, tempdir))

	def _start_post_builddir_lock(self, lock_future=None, start_ipc_daemon=False):
		if lock_future is not None:
			if lock_future is not self._start_future:
				raise AssertionError('lock_future is not self._start_future')
			self._start_future = None
			if lock_future.cancelled():
				self._build_dir = None
				self.cancelled = True
				self._was_cancelled()
				self._async_wait()
				return

			lock_future.result()

		if start_ipc_daemon:
			self.settings['PORTAGE_IPC_DAEMON'] = "1"
			self._start_ipc_daemon()

		if self.fd_pipes is None:
			self.fd_pipes = {}
		null_fd = None
		if 0 not in self.fd_pipes and \
			self.phase not in self._phases_interactive_whitelist and \
			"interactive" not in self.settings.get("PROPERTIES", "").split():
			null_fd = os.open('/dev/null', os.O_RDONLY)
			self.fd_pipes[0] = null_fd

		try:
			SpawnProcess._start(self)
		finally:
			if null_fd is not None:
				os.close(null_fd)

	def testLogfile(self):
		logfile = None
		try:
			fd, logfile = tempfile.mkstemp()
			os.close(fd)
			null_fd = os.open('/dev/null', os.O_RDWR)
			test_string = 2 * "blah blah blah\n"
			task_scheduler = TaskScheduler()
			proc = SpawnProcess(
				args=[BASH_BINARY, "-c",
				"echo -n '%s'" % test_string],
				env={}, fd_pipes={0:sys.stdin.fileno(), 1:null_fd, 2:null_fd},
				scheduler=task_scheduler.sched_iface,
				logfile=logfile)
			task_scheduler.add(proc)
			task_scheduler.run()
			os.close(null_fd)
			f = codecs.open(_unicode_encode(logfile,
				encoding=_encodings['fs'], errors='strict'),
				mode='r', encoding=_encodings['content'], errors='strict')
			log_content = f.read()
			f.close()
			# When logging passes through a pty, this comparison will fail
			# unless the oflag terminal attributes have the termios.OPOST
			# bit disabled. Otherwise, tranformations such as \n -> \r\n
			# may occur.
			self.assertEqual(test_string, log_content)
		finally:
			if logfile:
				try:
					os.unlink(logfile)
				except EnvironmentError as e:
					if e.errno != errno.ENOENT:
						raise
					del e

	def _check_sig_key(self):
		null_fd = os.open('/dev/null', os.O_RDONLY)
		popen_proc = PopenProcess(proc=subprocess.Popen(
			["gpg", "--verify", self._manifest_path],
			stdin=null_fd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT),
			pipe_reader=PipeReader())
		os.close(null_fd)
		popen_proc.pipe_reader.input_files = {
			"producer" : popen_proc.proc.stdout}
		self._start_task(popen_proc, self._check_sig_key_exit)

	def _start(self):
		self._files = self._files_dict()
		input_fd = os.open(self.input_fifo, os.O_RDONLY|os.O_NONBLOCK)
		self._files.pipe_in = os.fdopen(input_fd, 'rb')

		self._reg_id = self.scheduler.register(
			self._files.pipe_in.fileno(),
			self._registered_events, self._input_handler)

		self._registered = True

	def _reopen_input(self):
		"""
		Re-open the input stream, in order to suppress
		POLLHUP events (bug #339976).
		"""
		self.scheduler.unregister(self._reg_id)
		os.close(self._files.pipe_in)
		self._files.pipe_in = \
			os.open(self.input_fifo, os.O_RDONLY|os.O_NONBLOCK)
		self._reg_id = self.scheduler.register(
			self._files.pipe_in,
			self._registered_events, self._input_handler)

	def _start(self):
		self._files = self._files_dict()

		# File streams are in unbuffered mode since we do atomic
		# read and write of whole pickles.
		self._files.pipe_in = \
			os.open(self.input_fifo, os.O_RDONLY|os.O_NONBLOCK)

		self._reg_id = self.scheduler.register(
			self._files.pipe_in,
			self._registered_events, self._input_handler)

		self._registered = True

def hardlink_lockfile(lockfilename, max_wait=14400):
	"""Does the NFS, hardlink shuffle to ensure locking on the disk.
	We create a PRIVATE lockfile, that is just a placeholder on the disk.
	Then we HARDLINK the real lockfile to that private file.
	If our file can 2 references, then we have the lock. :)
	Otherwise we lather, rise, and repeat.
	We default to a 4 hour timeout.
	"""

	start_time = time.time()
	myhardlock = hardlock_name(lockfilename)
	reported_waiting = False
	
	while(time.time() < (start_time + max_wait)):
		# We only need it to exist.
		myfd = os.open(myhardlock, os.O_CREAT|os.O_RDWR,0o660)
		os.close(myfd)
	
		if not os.path.exists(myhardlock):
			raise FileNotFound(
				_("Created lockfile is missing: %(filename)s") % \
				{"filename" : myhardlock})

		try:
			res = os.link(myhardlock, lockfilename)
		except OSError:
			pass

		if hardlink_is_mine(myhardlock, lockfilename):
			# We have the lock.
			if reported_waiting:
				writemsg("\n", noiselevel=-1)
			return True

		if reported_waiting:
			writemsg(".", noiselevel=-1)
		else:
			reported_waiting = True
			from portage.const import PORTAGE_BIN_PATH
			msg = _("\nWaiting on (hardlink) lockfile: (one '.' per 3 seconds)\n"
				"%(bin_path)s/clean_locks can fix stuck locks.\n"
				"Lockfile: %(lockfilename)s\n") % \
				{"bin_path": PORTAGE_BIN_PATH, "lockfilename": lockfilename}
			writemsg(msg, noiselevel=-1)
		time.sleep(3)
	
	os.unlink(myhardlock)
	return False

   def __init__(self, environment):
      self.conf = environment
      pidfile = open(self.conf.get('pid_file'), 'w')

      if (self.conf.get('no_daemon') == False):
         print "forking to background"
         if (os.fork() == 0):
             os.setpgid(0,0);
             pidfile.write(str(os.getpid()));
             pidfile.close();
             fd = os.open("/dev/null", os.O_WRONLY);
             os.dup2(fd,1);
             os.close(fd);
             #self.main_loop()
         else:
            sys.exit()

      else:
           print "Keeping in foreground"
           pidfile.write(str(os.getpid()));
           pidfile.close();

 def testLogfile(self):
     logfile = None
     try:
         fd, logfile = tempfile.mkstemp()
         os.close(fd)
         null_fd = os.open("/dev/null", os.O_RDWR)
         test_string = 2 * "blah blah blah\n"
         scheduler = PollScheduler().sched_iface
         proc = SpawnProcess(
             args=[BASH_BINARY, "-c", "echo -n '%s'" % test_string],
             env={},
             fd_pipes={0: sys.stdin.fileno(), 1: null_fd, 2: null_fd},
             scheduler=scheduler,
             logfile=logfile,
         )
         proc.start()
         os.close(null_fd)
         self.assertEqual(proc.wait(), os.EX_OK)
         f = io.open(
             _unicode_encode(logfile, encoding=_encodings["fs"], errors="strict"),
             mode="r",
             encoding=_encodings["content"],
             errors="strict",
         )
         log_content = f.read()
         f.close()
         # When logging passes through a pty, this comparison will fail
         # unless the oflag terminal attributes have the termios.OPOST
         # bit disabled. Otherwise, tranformations such as \n -> \r\n
         # may occur.
         self.assertEqual(test_string, log_content)
     finally:
         if logfile:
             try:
                 os.unlink(logfile)
             except EnvironmentError as e:
                 if e.errno != errno.ENOENT:
                     raise
                 del e

	def _run(self):

		syncfs_failed = False
		syncfs = self._get_syncfs()

		if syncfs is not None:
			for path in self.paths:
				try:
					fd = os.open(path, os.O_RDONLY)
				except OSError:
					pass
				else:
					try:
						if syncfs(fd) != 0:
							# Happens with PyPy (bug #446610)
							syncfs_failed = True
					finally:
						os.close(fd)

		if syncfs is None or syncfs_failed:
			return 1
		return os.EX_OK

	def _send_reply(self, reply):
		# File streams are in unbuffered mode since we do atomic
		# read and write of whole pickles. Use non-blocking mode so
		# we don't hang if the client is killed before we can send
		# the reply. We rely on the client opening the other side
		# of this fifo before it sends its request, since otherwise
		# we'd have a race condition with this open call raising
		# ENXIO if the client hasn't opened the fifo yet.
		try:
			output_fd = os.open(self.output_fifo,
				os.O_WRONLY | os.O_NONBLOCK)
			try:
				os.write(output_fd, pickle.dumps(reply))
			finally:
				os.close(output_fd)
		except OSError as e:
			# This probably means that the client has been killed,
			# which causes open to fail with ENXIO.
			writemsg_level(
				"!!! EbuildIpcDaemon %s: %s\n" % \
				(_('failed to send reply'), e),
				level=logging.ERROR, noiselevel=-1)

	def testLogfile(self):
		from portage import settings, spawn
		from tempfile import mkstemp
		logfile = None
		try:
			fd, logfile = mkstemp()
			os.close(fd)
			null_fd = os.open('/dev/null', os.O_RDWR)
			test_string = 2 * "blah blah blah\n"
			# Test cases are unique because they run inside src_test() which
			# may or may not already be running within a sandbox. Interaction
			# with SANDBOX_* variables may trigger unwanted sandbox violations
			# that are only reproducible with certain combinations of sandbox,
			# usersandbox, and userpriv FEATURES. Attempts to filter SANDBOX_*
			# variables can interfere with a currently running sandbox
			# instance. Therefore, use free=1 here to avoid potential
			# interactions (see bug #190268).
			spawn("echo -n '%s'" % test_string, settings, logfile=logfile,
				free=1, fd_pipes={0:sys.stdin.fileno(), 1:null_fd, 2:null_fd})
			os.close(null_fd)
			f = codecs.open(_unicode_encode(logfile,
				encoding=_encodings['fs'], errors='strict'),
				mode='r', encoding=_encodings['content'], errors='strict')
			log_content = f.read()
			f.close()
			# When logging passes through a pty, this comparison will fail
			# unless the oflag terminal attributes have the termios.OPOST
			# bit disabled. Otherwise, tranformations such as \n -> \r\n
			# may occur.
			self.assertEqual(test_string, log_content)
		finally:
			if logfile:
				try:
					os.unlink(logfile)
				except EnvironmentError as e:
					if e.errno != errno.ENOENT:
						raise
					del e

	def _reopen_input(self):
		"""
		Re-open the input stream, in order to suppress
		POLLHUP events (bug #339976).
		"""
		self.scheduler.remove_reader(self._files.pipe_in)
		os.close(self._files.pipe_in)
		self._files.pipe_in = \
			os.open(self.input_fifo, os.O_RDONLY|os.O_NONBLOCK)

		# FD_CLOEXEC is enabled by default in Python >=3.4.
		if sys.hexversion < 0x3040000 and fcntl is not None:
			try:
				fcntl.FD_CLOEXEC
			except AttributeError:
				pass
			else:
				fcntl.fcntl(self._files.pipe_in, fcntl.F_SETFD,
					fcntl.fcntl(self._files.pipe_in,
						fcntl.F_GETFD) | fcntl.FD_CLOEXEC)

		self.scheduler.add_reader(
			self._files.pipe_in,
			self._input_handler)

	def _start(self):
		self._files = self._files_dict()

		# File streams are in unbuffered mode since we do atomic
		# read and write of whole pickles.
		self._files.pipe_in = \
			os.open(self.input_fifo, os.O_RDONLY|os.O_NONBLOCK)

		# FD_CLOEXEC is enabled by default in Python >=3.4.
		if sys.hexversion < 0x3040000 and fcntl is not None:
			try:
				fcntl.FD_CLOEXEC
			except AttributeError:
				pass
			else:
				fcntl.fcntl(self._files.pipe_in, fcntl.F_SETFD,
					fcntl.fcntl(self._files.pipe_in,
						fcntl.F_GETFD) | fcntl.FD_CLOEXEC)

		self.scheduler.add_reader(
			self._files.pipe_in,
			self._input_handler)

		self._registered = True