Python os.open() Examples

def __connect(self):
        device_addr, hidraw_device, event_device = self.__find_device()
        if device_addr is None:
            return False
        self.__report_fd = os.open(hidraw_device, os.O_RDWR | os.O_NONBLOCK)
        self.__fd = FileIO(self.__report_fd, "rb+", closefd=False)
        self.__input_device = InputDevice(event_device)
        self.__input_device.grab()
        buf = bytearray(38)
        buf[0] = 0x02
        try:
            return bool(fcntl.ioctl(self.__fd, 3223734279, bytes(buf)))
        except:
            pass
        if self.recv():
            self.update_controller() 

def _get_terminal_size_linux():
    def ioctl_GWINSZ(fd):
        try:
            import fcntl
            import termios
            cr = struct.unpack('hh',
                               fcntl.ioctl(fd, termios.TIOCGWINSZ, '1234'))
            return cr
        except:
            pass
    cr = ioctl_GWINSZ(0) or ioctl_GWINSZ(1) or ioctl_GWINSZ(2)
    if not cr:
        try:
            fd = os.open(os.ctermid(), os.O_RDONLY)
            cr = ioctl_GWINSZ(fd)
            os.close(fd)
        except:
            pass
    if not cr:
        try:
            cr = (os.environ['LINES'], os.environ['COLUMNS'])
        except:
            return None
    return int(cr[1]), int(cr[0]) 

def do_save(self, subcmd, opts, *dirs):
        """${cmd_name}: save changelog information for snapshot

        ${cmd_usage}
        ${cmd_option_list}
        """

        if not opts.dir:
            raise Exception("need --dir option")
        if not os.path.isdir(opts.dir):
            raise Exception("%s must be a directory" % opts.dir)
        if not opts.snapshot:
            raise Exception("missing snapshot option")

        f = open(os.path.join(opts.dir, opts.snapshot), 'wb')
        pickle.dump([data_version, self.readChangeLogs(dirs)], f) 

def atomic_writer(file_path, mode):
    """Atomic file writer.

    :param file_path: path of file to write to.
    :type file_path: ``unicode``
    :param mode: sames as for `func:open`
    :type mode: string

    .. versionadded:: 1.12

    Context manager that ensures the file is only written if the write
    succeeds. The data is first written to a temporary file.

    """
    temp_suffix = '.aw.temp'
    temp_file_path = file_path + temp_suffix
    with open(temp_file_path, mode) as file_obj:
        try:
            yield file_obj
            os.rename(temp_file_path, file_path)
        finally:
            try:
                os.remove(temp_file_path)
            except (OSError, IOError):
                pass 

def freebsd_tun_alloc(self, dev, flags):
		try:
			sockfd = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
			ifr = struct.pack('<16si', 'tun', 0)
			self.iface_name = fcntl.ioctl(sockfd, self.IOCTL_FREEBSD_SIOCIFCREATE2, ifr)
			self.iface_name = self.iface_name.rstrip("\x00")

			buff = array.array('c', dev+"\x00")
			caddr_t, _ = buff.buffer_info()
			ifr = struct.pack('16sP', self.iface_name, caddr_t);

			fcntl.ioctl(sockfd, self.IOCTL_FREEBSD_SIOCSIFNAME, ifr)
			tun = os.open("/dev/"+self.iface_name, os.O_RDWR | os.O_NONBLOCK)
			self.iface_name = dev

		except IOError as e:
			print e
			common.internal_print("Error: Cannot create tunnel. Is {0} in use?".format(dev), -1)
			sys.exit(-1)

		return tun 

def __init__(self, video_device, width, height, channels=3, input_pixfmt='RGB'):
        
        if channels != 3:
            raise NotImplementedError('Code only supports inputs with 3 channels right now. You tried to intialize with {} channels'.format(channels))

        if input_pixfmt != 'RGB':
            raise NotImplementedError('Code only supports RGB pixfmt. You tried to intialize with {}'.format(input_pixfmt))
        
        if not os.path.exists(video_device):
            sys.stderr.write('\n--- Make sure the v4l2loopback kernel module is loaded ---\n')
            sys.stderr.write('sudo modprobe v4l2loopback devices=1\n\n')
            raise FileNotFoundError('device does not exist: {}'.format(video_device))

        self._channels = channels
        self._video_device = os.open(video_device, os.O_WRONLY | os.O_SYNC)
                    
        self._settings = _v4l2.v4l2_format()
        self._settings.type = _v4l2.V4L2_BUF_TYPE_VIDEO_OUTPUT
        self._settings.fmt.pix.pixelformat = _v4l2.V4L2_PIX_FMT_YUYV
        self._settings.fmt.pix.width = width
        self._settings.fmt.pix.height = height
        self._settings.fmt.pix.field = _v4l2.V4L2_FIELD_NONE
        self._settings.fmt.pix.bytesperline = width * 2
        self._settings.fmt.pix.sizeimage = width * height * 2
        self._settings.fmt.pix.colorspace = _v4l2.V4L2_COLORSPACE_JPEG

        self._buffer = np.zeros((self._settings.fmt.pix.height, 2*self._settings.fmt.pix.width), dtype=np.uint8)

        self._yuv = np.zeros((self._settings.fmt.pix.height, self._settings.fmt.pix.width, 3), dtype=np.uint8)
        self._ones = np.ones((self._settings.fmt.pix.height, self._settings.fmt.pix.width, 1), dtype=np.uint8)
        self._rgb2yuv = np.array([[0.299, 0.587, 0.114, 0],
                                  [-0.168736, -0.331264, 0.5, 128],
                                  [0.5, -0.418688, -0.081312, 128]])
        
        fcntl.ioctl(self._video_device, _v4l2.VIDIOC_S_FMT, self._settings) 

def daemonize(logfile = None):
    # Fork once
    if os.fork() != 0:
        os._exit(0)
    # Create new session
    os.setsid()
    if os.fork() != 0:
        os._exit(0)
    os.chdir('/')
    fd = os.open('/dev/null', os.O_RDWR)
    os.dup2(fd, sys.__stdin__.fileno())
    if logfile != None:
        fake_stdout = open(logfile, 'a', 1)
        sys.stdout = fake_stdout
        sys.stderr = fake_stdout
        fd = fake_stdout.fileno()
    os.dup2(fd, sys.__stdout__.fileno())
    os.dup2(fd, sys.__stderr__.fileno())
    if logfile == None:
        os.close(fd) 

def computehash(self, hashtype="md5", chunksize=524288):
        """ return hexdigest of hashvalue for this file. """
        try:
            try:
                import hashlib as mod
            except ImportError:
                if hashtype == "sha1":
                    hashtype = "sha"
                mod = __import__(hashtype)
            hash = getattr(mod, hashtype)()
        except (AttributeError, ImportError):
            raise ValueError("Don't know how to compute %r hash" %(hashtype,))
        f = self.open('rb')
        try:
            while 1:
                buf = f.read(chunksize)
                if not buf:
                    return hash.hexdigest()
                hash.update(buf)
        finally:
            f.close() 

def clear_scene_and_import_fbx(filepath):
    """
    Clear the whole scene and import fbx file into the empty scene.

    :param filepath: filepath for fbx file
    """
    # redirect blender output info
    logfile = 'blender_render.log'
    open(logfile, 'w').close()
    old = os.dup(1)
    sys.stdout.flush()
    os.close(1)
    os.open(logfile, os.O_WRONLY)

    bpy.ops.wm.read_homefile(filepath=HOME_FILE_PATH)
    bpy.ops.import_scene.fbx(filepath=filepath)

    os.close(1)
    os.dup(old)
    os.close(old) 

def __init__(self, targetfd, tmpfile=None, now=True, patchsys=False):
        """ save targetfd descriptor, and open a new
            temporary file there.  If no tmpfile is
            specified a tempfile.Tempfile() will be opened
            in text mode.
        """
        self.targetfd = targetfd
        if tmpfile is None and targetfd != 0:
            f = tempfile.TemporaryFile('wb+')
            tmpfile = dupfile(f, encoding="UTF-8")
            f.close()
        self.tmpfile = tmpfile
        self._savefd = os.dup(self.targetfd)
        if patchsys:
            self._oldsys = getattr(sys, patchsysdict[targetfd])
        if now:
            self.start() 

def start(self):
        try:
            os.fstat(self._savefd)
        except OSError:
            raise ValueError("saved filedescriptor not valid, "
                "did you call start() twice?")
        if self.targetfd == 0 and not self.tmpfile:
            fd = os.open(devnullpath, os.O_RDONLY)
            os.dup2(fd, 0)
            os.close(fd)
            if hasattr(self, '_oldsys'):
                setattr(sys, patchsysdict[self.targetfd], DontReadFromInput())
        else:
            os.dup2(self.tmpfile.fileno(), self.targetfd)
            if hasattr(self, '_oldsys'):
                setattr(sys, patchsysdict[self.targetfd], self.tmpfile) 

def _cleanup(self):
        """Clean up temporary files after the userscript finished."""
        if self._cleaned_up:
            return
        assert self._filepath is not None

        try:
            with open(self._filepath, 'r', encoding='utf-8') as f:
                for line in f:
                    self.got_cmd.emit(line.rstrip())
        except OSError:
            log.procs.exception("Failed to read command file!")
        except UnicodeDecodeError as e:
            log.misc.error("Invalid unicode in userscript output: {}"
                           .format(e))

        super()._cleanup()
        self.finished.emit() 

def start(self) -> None:
        self.current_frame = [0 for _ in range(self.bars)]
        self.growing_frame = b""
        try:
            # delete old contents of the pipe
            os.remove(self.cava_fifo_path)
        except FileNotFoundError:
            # the file does not exist
            pass
        try:
            os.mkfifo(self.cava_fifo_path)
        except FileExistsError:
            # the file already exists
            logging.info("%s already exists while starting", self.cava_fifo_path)

        self.cava_process = subprocess.Popen(
            ["cava", "-p", os.path.join(settings.BASE_DIR, "config/cava.config")],
            cwd=settings.BASE_DIR,
        )
        # cava_fifo = open(cava_fifo_path, 'r')
        self.cava_fifo = os.open(self.cava_fifo_path, os.O_RDONLY | os.O_NONBLOCK) 

def open_workflowdir(self):
        """Open the workflow's :attr:`workflowdir` in Finder."""
        subprocess.call(['open', self.workflowdir]) 

def load(cls, file_obj):
        """Load serialized object from open JSON file.

        .. versionadded:: 1.8

        :param file_obj: file handle
        :type file_obj: ``file`` object
        :returns: object loaded from JSON file
        :rtype: object

        """

        return json.load(file_obj) 

def dump(cls, obj, file_obj):
        """Serialize object ``obj`` to open JSON file.

        .. versionadded:: 1.8

        :param obj: Python object to serialize
        :type obj: JSON-serializable data structure
        :param file_obj: file handle
        :type file_obj: ``file`` object

        """

        return json.dump(obj, file_obj, indent=2, encoding='utf-8') 

def json2npy():
    data_root = OUT_DATA_DIR

    character_names = os.listdir(data_root)
    print(character_names)

    total_num = 0
    for char in character_names:
        char_dir = os.path.join(data_root, char)
        animation_names = os.listdir(char_dir)

        for anim in animation_names:
            joint_dir = os.path.join(char_dir, anim, 'jointsDict')

            nr_files = len(os.listdir(joint_dir))
            motion = []
            for i in range(0, nr_files):
                with open(os.path.join(joint_dir, '%04d_keypoints.json' % i)) as f:
                    info = json.load(f)
                    joint = np.array(info['pose_keypoints_3d']).reshape((-1, 3))
                motion.append(joint[:15, :])

            motion = np.stack(motion, axis=2)
            save_path = os.path.join(char_dir, anim, '{}.npy'.format(anim))
            print(save_path)
            np.save(save_path, motion) 

def open_datadir(self):
        """Open the workflow's :attr:`datadir` in Finder."""
        subprocess.call(['open', self.datadir]) 

def readRpmHeader(self, filename):
        """ Read an rpm header. """
        fd = os.open(filename, os.O_RDONLY)
        h = self.readRpmHeaderFD(fd)
        os.close(fd)
        return h 

def open_help(self):
        """Open :attr:`help_url` in default browser"""
        subprocess.call(['open', self.help_url])

        return 'Opening workflow help URL in browser'

    ####################################################################
    # Helper methods
    #################################################################### 

def create_file(self, prefix, filename):
        full_file_name = "%s%s.txt" % (prefix, filename)
        file_path = "%s%s" % (self.settings.get_data_folder_path(), full_file_name)
        try:
            file = os_open(file_path, O_CREAT | O_EXCL)
            os_close(file)
            return full_file_name
        except IOError as e:
            log.error("Failed to create a new file! Error: %s", e) 

def acquire(self, blocking=True):
        """Acquire the lock if possible.

        If the lock is in use and ``blocking`` is ``False``, return
        ``False``.

        Otherwise, check every `self.delay` seconds until it acquires
        lock or exceeds `self.timeout` and raises an exception.

        """
        start = time.time()
        while True:
            try:
                fd = os.open(self.lockfile, os.O_CREAT | os.O_EXCL | os.O_RDWR)
                with os.fdopen(fd, 'w') as fd:
                    fd.write('{0}'.format(os.getpid()))
                break
            except OSError as err:
                if err.errno != errno.EEXIST:  # pragma: no cover
                    raise
                if self.timeout and (time.time() - start) >= self.timeout:
                    raise AcquisitionError('Lock acquisition timed out.')
                if not blocking:
                    return False
                time.sleep(self.delay)

        self._locked = True
        return True 

def _read_num_file(self, path):
        """
        Reads a numeric value from a sysfs file that contains only a number.
        """

        with open(path, 'r') as f:
            raw = f.read()
            return int(raw) 

def __init__(self):
        # Open a pair of null files
        self.null_fds = [os.open(os.devnull, os.O_RDWR) for _ in range(2)]

        # Save the actual stdout (1) and stderr (2) file descriptors.
        self.save_fds = (os.dup(1), os.dup(2)) 

def __init__(self, filepath, parent=None):
        super().__init__(parent)
        self._filepath = filepath
        # We open as R/W so we never get EOF and have to reopen the pipe.
        # See http://www.outflux.net/blog/archives/2008/03/09/using-select-on-a-fifo/
        # We also use os.open and os.fdopen rather than built-in open so we
        # can add O_NONBLOCK.
        # pylint: disable=no-member,useless-suppression
        fd = os.open(filepath, os.O_RDWR | os.O_NONBLOCK)
        # pylint: enable=no-member,useless-suppression
        self._fifo = os.fdopen(fd, 'r')
        self._notifier = QSocketNotifier(typing.cast(sip.voidptr, fd),
                                         QSocketNotifier.Read, self)
        self._notifier.activated.connect(  # type: ignore[attr-defined]
            self.read_line) 

def dupfile(f, mode=None, buffering=0, raising=False, encoding=None):
    """ return a new open file object that's a duplicate of f

        mode is duplicated if not given, 'buffering' controls
        buffer size (defaulting to no buffering) and 'raising'
        defines whether an exception is raised when an incompatible
        file object is passed in (if raising is False, the file
        object itself will be returned)
    """
    try:
        fd = f.fileno()
        mode = mode or f.mode
    except AttributeError:
        if raising:
            raise
        return f
    newfd = os.dup(fd)
    if sys.version_info >= (3,0):
        if encoding is not None:
            mode = mode.replace("b", "")
            buffering = True
        return os.fdopen(newfd, mode, buffering, encoding, closefd=True)
    else:
        f = os.fdopen(newfd, mode, buffering)
        if encoding is not None:
            return EncodedFile(f, encoding)
        return f 

def copychunked(src, dest):
    chunksize = 524288  # half a meg of bytes
    fsrc = src.open('rb')
    try:
        fdest = dest.open('wb')
        try:
            while 1:
                buf = fsrc.read(chunksize)
                if not buf:
                    break
                fdest.write(buf)
        finally:
            fdest.close()
    finally:
        fsrc.close() 

def ensure(self, *args, **kwargs):
        """ ensure that an args-joined path exists (by default as
            a file). if you specify a keyword argument 'dir=True'
            then the path is forced to be a directory path.
        """
        p = self.join(*args)
        if kwargs.get('dir', 0):
            return p._ensuredirs()
        else:
            p.dirpath()._ensuredirs()
            if not p.check(file=1):
                p.open('w').close()
            return p 

def write_text(self, data, encoding, ensure=False):
        """ write text data into path using the specified encoding.
        If ensure is True create missing parent directories.
        """
        if ensure:
            self.dirpath().ensure(dir=1)
        with self.open('w', encoding=encoding) as f:
            f.write(data) 

def write_binary(self, data, ensure=False):
        """ write binary data into path.   If ensure is True create
        missing parent directories.
        """
        if ensure:
            self.dirpath().ensure(dir=1)
        with self.open('wb') as f:
            f.write(data)