Python os.O_WRONLY Examples

def test_flush_error_on_close(self):
        # raw file
        # Issue #5700: io.FileIO calls flush() after file closed
        self.check_flush_error_on_close(support.TESTFN, 'wb', buffering=0)
        fd = os.open(support.TESTFN, os.O_WRONLY|os.O_CREAT)
        self.check_flush_error_on_close(fd, 'wb', buffering=0)
        fd = os.open(support.TESTFN, os.O_WRONLY|os.O_CREAT)
        self.check_flush_error_on_close(fd, 'wb', buffering=0, closefd=False)
        os.close(fd)
        # buffered io
        self.check_flush_error_on_close(support.TESTFN, 'wb')
        fd = os.open(support.TESTFN, os.O_WRONLY|os.O_CREAT)
        self.check_flush_error_on_close(fd, 'wb')
        fd = os.open(support.TESTFN, os.O_WRONLY|os.O_CREAT)
        self.check_flush_error_on_close(fd, 'wb', closefd=False)
        os.close(fd)
        # text io
        self.check_flush_error_on_close(support.TESTFN, 'w')
        fd = os.open(support.TESTFN, os.O_WRONLY|os.O_CREAT)
        self.check_flush_error_on_close(fd, 'w')
        fd = os.open(support.TESTFN, os.O_WRONLY|os.O_CREAT)
        self.check_flush_error_on_close(fd, 'w', closefd=False)
        os.close(fd) 

def render_without_output(use_antialiasing=True):
    # redirect output to log file
    logfile = 'blender_render.log'
    open(logfile, 'a').close()
    old = os.dup(1)
    sys.stdout.flush()
    os.close(1)
    os.open(logfile, os.O_WRONLY)
    # Render
    bpy.context.scene.render.use_antialiasing = use_antialiasing
    bpy.ops.render.render(write_still=True)
    # disable output redirection
    os.close(1)
    os.dup(old)
    os.close(old)


# Creating a lamp with an appropriate energy 

def write_pid_to_pidfile(pidfile_path):
    """ Write the PID in the named PID file.

        Get the numeric process ID (“PID”) of the current process
        and write it to the named file as a line of text.

        """
    open_flags = (os.O_CREAT | os.O_EXCL | os.O_WRONLY)
    open_mode = 0o644
    pidfile_fd = os.open(pidfile_path, open_flags, open_mode)
    pidfile = os.fdopen(pidfile_fd, 'w')

    # According to the FHS 2.3 section on PID files in /var/run:
    #
    #   The file must consist of the process identifier in
    #   ASCII-encoded decimal, followed by a newline character. For
    #   example, if crond was process number 25, /var/run/crond.pid
    #   would contain three characters: two, five, and newline.

    pid = os.getpid()
    pidfile.write("%s\n" % pid)
    pidfile.close() 

def write_pid_to_pidfile(pidfile_path):
    """ Write the PID in the named PID file.

        Get the numeric process ID (“PID”) of the current process
        and write it to the named file as a line of text.

        """
    open_flags = (os.O_CREAT | os.O_EXCL | os.O_WRONLY)
    open_mode = 0o644
    pidfile_fd = os.open(pidfile_path, open_flags, open_mode)
    pidfile = os.fdopen(pidfile_fd, 'w')

    # According to the FHS 2.3 section on PID files in /var/run:
    #
    #   The file must consist of the process identifier in
    #   ASCII-encoded decimal, followed by a newline character. For
    #   example, if crond was process number 25, /var/run/crond.pid
    #   would contain three characters: two, five, and newline.

    pid = os.getpid()
    pidfile.write("%s\n" % pid)
    pidfile.close() 

def write_pid_to_pidfile(pidfile_path):
    """ Write the PID in the named PID file.

        Get the numeric process ID (“PID”) of the current process
        and write it to the named file as a line of text.

        """
    open_flags = (os.O_CREAT | os.O_EXCL | os.O_WRONLY)
    open_mode = 0o644
    pidfile_fd = os.open(pidfile_path, open_flags, open_mode)
    pidfile = os.fdopen(pidfile_fd, 'w')

    # According to the FHS 2.3 section on PID files in /var/run:
    #
    #   The file must consist of the process identifier in
    #   ASCII-encoded decimal, followed by a newline character. For
    #   example, if crond was process number 25, /var/run/crond.pid
    #   would contain three characters: two, five, and newline.

    pid = os.getpid()
    pidfile.write("%s\n" % pid)
    pidfile.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 test__interface_by_mac_not_found(self, mock_ipr):
        mock_ipr_instance = mock.MagicMock()
        mock_ipr_instance.link_lookup.return_value = []
        mock_ipr().__enter__.return_value = mock_ipr_instance

        fd_mock = mock.mock_open()
        open_mock = mock.Mock()
        isfile_mock = mock.Mock()
        with mock.patch('os.open', open_mock), mock.patch.object(
                os, 'fdopen', fd_mock), mock.patch.object(
                os.path, 'isfile', isfile_mock):
            self.assertRaises(wz_exceptions.HTTPException,
                              self.test_plug._interface_by_mac,
                              FAKE_MAC_ADDRESS.upper())
        open_mock.assert_called_once_with('/sys/bus/pci/rescan', os.O_WRONLY)
        fd_mock().write.assert_called_once_with('1') 

def _interface_by_mac(self, mac):
        try:
            with pyroute2.IPRoute() as ipr:
                idx = ipr.link_lookup(address=mac)[0]
                addr = ipr.get_links(idx)[0]
                for attr in addr['attrs']:
                    if attr[0] == 'IFLA_IFNAME':
                        return attr[1]
        except Exception as e:
            LOG.info('Unable to find interface with MAC: %s, rescanning '
                     'and returning 404. Reported error: %s', mac, str(e))

        # Poke the kernel to re-enumerate the PCI bus.
        # We have had cases where nova hot plugs the interface but
        # the kernel doesn't get the memo.
        filename = '/sys/bus/pci/rescan'
        flags = os.O_WRONLY
        if os.path.isfile(filename):
            with os.fdopen(os.open(filename, flags), 'w') as rescan_file:
                rescan_file.write('1')
        raise exceptions.HTTPException(
            response=webob.Response(json=dict(
                details="No suitable network interface found"), status=404)) 

def upload_certificate(self, lb_id, filename):
        self._check_ssl_filename_format(filename)

        # create directory if not already there
        if not os.path.exists(self._cert_dir(lb_id)):
            os.makedirs(self._cert_dir(lb_id))

        stream = Wrapped(flask.request.stream)
        file = self._cert_file_path(lb_id, filename)
        flags = os.O_WRONLY | os.O_CREAT
        # mode 00600
        mode = stat.S_IRUSR | stat.S_IWUSR
        with os.fdopen(os.open(file, flags, mode), 'wb') as crt_file:
            b = stream.read(BUFFER)
            while b:
                crt_file.write(b)
                b = stream.read(BUFFER)

        resp = webob.Response(json=dict(message='OK'))
        resp.headers['ETag'] = stream.get_md5()
        return resp 

def install_netns_systemd_service():
    os_utils = osutils.BaseOS.get_os_util()

    flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
    # mode 00644
    mode = (stat.S_IRUSR | stat.S_IWUSR | stat.S_IRGRP | stat.S_IROTH)

    # TODO(bcafarel): implement this for other init systems
    # netns handling depends on a separate unit file
    netns_path = os.path.join(consts.SYSTEMD_DIR,
                              consts.AMP_NETNS_SVC_PREFIX + '.service')

    jinja_env = jinja2.Environment(
        autoescape=True, loader=jinja2.FileSystemLoader(os.path.dirname(
            os.path.realpath(__file__)
        ) + consts.AGENT_API_TEMPLATES))

    if not os.path.exists(netns_path):
        with os.fdopen(os.open(netns_path, flags, mode), 'w') as text_file:
            text = jinja_env.get_template(
                consts.AMP_NETNS_SVC_PREFIX + '.systemd.j2').render(
                    amphora_nsname=consts.AMPHORA_NAMESPACE,
                    HasIFUPAll=os_utils.has_ifup_all())
            text_file.write(text) 

def upload_config(self):
        try:
            stream = flask.request.stream
            file_path = cfg.find_config_files(project=CONF.project,
                                              prog=CONF.prog)[0]
            flags = os.O_WRONLY | os.O_CREAT | os.O_TRUNC
            # mode 00600
            mode = stat.S_IRUSR | stat.S_IWUSR
            with os.fdopen(os.open(file_path, flags, mode), 'wb') as cfg_file:
                b = stream.read(BUFFER)
                while b:
                    cfg_file.write(b)
                    b = stream.read(BUFFER)

            CONF.mutate_config_files()
        except Exception as e:
            LOG.error("Unable to update amphora-agent configuration: "
                      "{}".format(str(e)))
            return webob.Response(json=dict(
                message="Unable to update amphora-agent configuration.",
                details=str(e)), status=500)

        return webob.Response(json={'message': 'OK'}, status=202) 

def redirect_io(log_file='/dev/null'):
    # Always redirect stdin.
    in_fd = os.open('/dev/null', os.O_RDONLY)
    try:
        os.dup2(in_fd, 0)
    finally:
        os.close(in_fd)

    out_fd = os.open(log_file, os.O_WRONLY | os.O_CREAT)
    try:
        os.dup2(out_fd, 2)
        os.dup2(out_fd, 1)
    finally:
        os.close(out_fd)

    sys.stdin = os.fdopen(0, 'r')
    sys.stdout = os.fdopen(1, 'w')
    sys.stderr = os.fdopen(2, 'w') 

def create_cleanup_lock(p):
    """crates a lock to prevent premature folder cleanup"""
    lock_path = get_lock_path(p)
    try:
        fd = os.open(str(lock_path), os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o644)
    except OSError as e:
        if e.errno == errno.EEXIST:
            raise EnvironmentError(
                "cannot create lockfile in {path}".format(path=p)
            ) from e

        else:
            raise
    else:
        pid = os.getpid()
        spid = str(pid).encode()
        os.write(fd, spid)
        os.close(fd)
        if not lock_path.is_file():
            raise EnvironmentError("lock path got renamed after successful creation")
        return lock_path 

def touch(self, mode=0o666, exist_ok=True):
        """
        Create this file with the given access mode, if it doesn't exist.
        """
        if self._closed:
            self._raise_closed()
        if exist_ok:
            # First try to bump modification time
            # Implementation note: GNU touch uses the UTIME_NOW option of
            # the utimensat() / futimens() functions.
            try:
                self._accessor.utime(self, None)
            except OSError:
                # Avoid exception chaining
                pass
            else:
                return
        flags = os.O_CREAT | os.O_WRONLY
        if not exist_ok:
            flags |= os.O_EXCL
        fd = self._raw_open(flags, mode)
        os.close(fd) 

def create_cleanup_lock(p):
    """crates a lock to prevent premature folder cleanup"""
    lock_path = get_lock_path(p)
    try:
        fd = os.open(str(lock_path), os.O_WRONLY | os.O_CREAT | os.O_EXCL, 0o644)
    except OSError as e:
        if e.errno == errno.EEXIST:
            raise EnvironmentError(
                "cannot create lockfile in {path}".format(path=p)
            ) from e

        else:
            raise
    else:
        pid = os.getpid()
        spid = str(pid).encode()
        os.write(fd, spid)
        os.close(fd)
        if not lock_path.is_file():
            raise EnvironmentError("lock path got renamed after successful creation")
        return lock_path 

def touch(self, mode=0o666, exist_ok=True):
        """
        Create this file with the given access mode, if it doesn't exist.
        """
        if self._closed:
            self._raise_closed()
        if exist_ok:
            # First try to bump modification time
            # Implementation note: GNU touch uses the UTIME_NOW option of
            # the utimensat() / futimens() functions.
            try:
                self._accessor.utime(self, None)
            except OSError:
                # Avoid exception chaining
                pass
            else:
                return
        flags = os.O_CREAT | os.O_WRONLY
        if not exist_ok:
            flags |= os.O_EXCL
        fd = self._raw_open(flags, mode)
        os.close(fd) 

def _init_dirs(self):
        test_dirs = ["a a", "b", "D_"]
        config = "improbable"
        root = tempfile.mkdtemp()

        def cleanup():
            try:
                os.removedirs(root)
            except (FileNotFoundError, OSError):
                pass

        os.chdir(root)

        for dir_ in test_dirs:
            os.mkdir(dir_, 0o0750)

            f = "{0}.toml".format(config)
            flags = os.O_WRONLY | os.O_CREAT
            rel_path = "{0}/{1}".format(dir_, f)
            abs_file_path = os.path.join(root, rel_path)
            with os.fdopen(os.open(abs_file_path, flags, 0o0640), "w") as fp:
                fp.write('key = "value is {0}"\n'.format(dir_))

        return root, config, cleanup 

def test_path_with_null_byte(self):
        fn = test_support.TESTFN
        fn_with_NUL = fn + '\0'
        self.addCleanup(test_support.unlink, fn)
        test_support.unlink(fn)
        fd = None
        try:
            with self.assertRaises(TypeError):
                fd = os.open(fn_with_NUL, os.O_WRONLY | os.O_CREAT) # raises
        finally:
            if fd is not None:
                os.close(fd)
        self.assertFalse(os.path.exists(fn))
        self.assertRaises(TypeError, os.mkdir, fn_with_NUL)
        self.assertFalse(os.path.exists(fn))
        open(fn, 'wb').close()
        self.assertRaises(TypeError, os.stat, fn_with_NUL) 

def writeToken(self):
        """
        Store details of the current connection in the named file.

        This can be used by :meth:`readToken` to re-authenticate at a later time.
        """
        # Write token file privately.
        with os.fdopen(os.open(self.tokenFile, os.O_WRONLY | os.O_CREAT, 0o600), "w") as f:
            # When opening files via os, truncation must be done manually.
            f.truncate()
            f.write(self.userId + "\n")
            f.write(self.tokens["skype"] + "\n")
            f.write(str(int(time.mktime(self.tokenExpiry["skype"].timetuple()))) + "\n")
            f.write(self.tokens["reg"] + "\n")
            f.write(str(int(time.mktime(self.tokenExpiry["reg"].timetuple()))) + "\n")
            f.write(self.msgsHost + "\n") 

def test_path_with_null_unicode(self):
        fn = test_support.TESTFN_UNICODE
        try:
            fn.encode(test_support.TESTFN_ENCODING)
        except (UnicodeError, TypeError):
            self.skipTest("Requires unicode filenames support")
        fn_with_NUL = fn + u'\0'
        self.addCleanup(test_support.unlink, fn)
        test_support.unlink(fn)
        fd = None
        try:
            with self.assertRaises(TypeError):
                fd = os.open(fn_with_NUL, os.O_WRONLY | os.O_CREAT) # raises
        finally:
            if fd is not None:
                os.close(fd)
        self.assertFalse(os.path.exists(fn))
        self.assertRaises(TypeError, os.mkdir, fn_with_NUL)
        self.assertFalse(os.path.exists(fn))
        open(fn, 'wb').close()
        self.assertRaises(TypeError, os.stat, fn_with_NUL) 

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 write_pid_to_pidfile(pidfile_path):
    """ Write the PID in the named PID file.

        Get the numeric process ID (“PID”) of the current process
        and write it to the named file as a line of text.

        """
    open_flags = (os.O_CREAT | os.O_EXCL | os.O_WRONLY)
    open_mode = 0o644
    pidfile_fd = os.open(pidfile_path, open_flags, open_mode)
    pidfile = os.fdopen(pidfile_fd, 'w')

    # According to the FHS 2.3 section on PID files in /var/run:
    #
    #   The file must consist of the process identifier in
    #   ASCII-encoded decimal, followed by a newline character. For
    #   example, if crond was process number 25, /var/run/crond.pid
    #   would contain three characters: two, five, and newline.

    pid = os.getpid()
    pidfile.write("%s\n" % pid)
    pidfile.close() 

def test_no_leaking(self):
        # Make sure we leak no resources
        if not mswindows:
            max_handles = 1026 # too much for most UNIX systems
        else:
            max_handles = 2050 # too much for (at least some) Windows setups
        handles = []
        try:
            for i in range(max_handles):
                try:
                    handles.append(os.open(test_support.TESTFN,
                                           os.O_WRONLY | os.O_CREAT))
                except OSError as e:
                    if e.errno != errno.EMFILE:
                        raise
                    break
            else:
                self.skipTest("failed to reach the file descriptor limit "
                    "(tried %d)" % max_handles)
            # Close a couple of them (should be enough for a subprocess)
            for i in range(10):
                os.close(handles.pop())
            # Loop creating some subprocesses. If one of them leaks some fds,
            # the next loop iteration will fail by reaching the max fd limit.
            for i in range(15):
                p = subprocess.Popen([sys.executable, "-c",
                                      "import sys;"
                                      "sys.stdout.write(sys.stdin.read())"],
                                     stdin=subprocess.PIPE,
                                     stdout=subprocess.PIPE,
                                     stderr=subprocess.PIPE)
                data = p.communicate(b"lime")[0]
                self.assertEqual(data, b"lime")
        finally:
            for h in handles:
                os.close(h)
            test_support.unlink(test_support.TESTFN) 

def test_fileobj_from_io_open(self):
        fd = os.open(self.filename, os.O_WRONLY | os.O_CREAT)
        with io.open(fd, "wb") as f:
            with gzip.GzipFile(fileobj=f, mode="w") as g:
                self.assertEqual(g.name, "") 

def test_fileobj_from_fdopen(self):
        # Issue #13781: Creating a GzipFile using a fileobj from os.fdopen()
        # should not embed the fake filename "<fdopen>" in the output file.
        fd = os.open(self.filename, os.O_WRONLY | os.O_CREAT)
        with os.fdopen(fd, "wb") as f:
            with gzip.GzipFile(fileobj=f, mode="w") as g:
                self.assertEqual(g.name, "") 

def requiresWriteAccess(self, path):
        if not os.access(path, os.W_OK):
            self.skipTest('requires write access to the installed location')
        filename = os.path.join(path, 'test_zipfile.try')
        try:
            fd = os.open(filename, os.O_WRONLY | os.O_CREAT)
            os.close(fd)
        except Exception:
            self.skipTest('requires write access to the installed location')
        unlink(filename) 

def test_osshlock(self):
        fd1 = os.open(test_support.TESTFN,
                      os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
        fd2 = os.open(test_support.TESTFN,
                      os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
        os.close(fd2)
        os.close(fd1)

        if hasattr(posix, "O_EXLOCK"):
            fd = os.open(test_support.TESTFN,
                         os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
            self.assertRaises(OSError, os.open, test_support.TESTFN,
                              os.O_RDONLY|os.O_EXLOCK|os.O_NONBLOCK)
            os.close(fd) 

def _store_cert(self):
        fd_mock = mock.mock_open()
        open_mock = mock.Mock()
        # Attempt to store the cert
        with mock.patch('os.open', open_mock), mock.patch.object(
                os, 'fdopen', fd_mock):
            cert_id = local_cert_mgr.LocalCertManager.store_cert(
                context=None,
                certificate=self.certificate,
                intermediates=self.intermediates,
                private_key=self.private_key,
                private_key_passphrase=self.private_key_passphrase
            )

        # Check that something came back
        self.assertIsNotNone(cert_id)

        # Verify the correct files were opened
        flags = os.O_WRONLY | os.O_CREAT
        mode = stat.S_IRUSR | stat.S_IWUSR  # mode 0600
        open_mock.assert_has_calls([
            mock.call(
                os.path.join('/tmp/{0}.crt'.format(cert_id)), flags, mode),
            mock.call(
                os.path.join('/tmp/{0}.key'.format(cert_id)), flags, mode),
            mock.call(
                os.path.join('/tmp/{0}.int'.format(cert_id)), flags, mode),
            mock.call(
                os.path.join('/tmp/{0}.pass'.format(cert_id)), flags, mode)
        ], any_order=True)

        # Verify the writes were made
        fd_mock().write.assert_has_calls([
            mock.call(self.certificate),
            mock.call(self.intermediates),
            mock.call(self.private_key),
            mock.call(self.private_key_passphrase)
        ], any_order=True)

        return cert_id 

def __init__(self, name, mode):
        mode = {
            "r": os.O_RDONLY,
            "w": os.O_WRONLY | os.O_CREAT | os.O_TRUNC,
        }[mode]
        if hasattr(os, "O_BINARY"):
            mode |= os.O_BINARY
        self.fd = os.open(name, mode, 0o666) 

def test_osexlock(self):
        fd = os.open(test_support.TESTFN,
                     os.O_WRONLY|os.O_EXLOCK|os.O_CREAT)
        self.assertRaises(OSError, os.open, test_support.TESTFN,
                          os.O_WRONLY|os.O_EXLOCK|os.O_NONBLOCK)
        os.close(fd)

        if hasattr(posix, "O_SHLOCK"):
            fd = os.open(test_support.TESTFN,
                         os.O_WRONLY|os.O_SHLOCK|os.O_CREAT)
            self.assertRaises(OSError, os.open, test_support.TESTFN,
                              os.O_WRONLY|os.O_EXLOCK|os.O_NONBLOCK)
            os.close(fd)