Python os.O_RDONLY Examples

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 _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 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 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 test_huntrleaks_fd_leak(self):
        # test --huntrleaks for file descriptor leak
        code = textwrap.dedent("""
            import os
            import unittest
            from test import support

            class FDLeakTest(unittest.TestCase):
                def test_leak(self):
                    fd = os.open(__file__, os.O_RDONLY)
                    # bug: never close the file descriptor

            def test_main():
                support.run_unittest(FDLeakTest)
        """)
        self.check_leak(code, 'file descriptors') 

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 test_fcntl_64_bit(self):
        # Issue #1309352: fcntl shouldn't fail when the third arg fits in a
        # C 'long' but not in a C 'int'.
        try:
            cmd = fcntl.F_NOTIFY
            # This flag is larger than 2**31 in 64-bit builds
            flags = fcntl.DN_MULTISHOT
        except AttributeError:
            self.skipTest("F_NOTIFY or DN_MULTISHOT unavailable")
        fd = os.open(os.path.dirname(os.path.abspath(TESTFN)), os.O_RDONLY)
        try:
            # This will raise OverflowError if issue1309352 is present.
            fcntl.fcntl(fd, cmd, flags)
        except IOError:
            pass  # Running on a system that doesn't support these flags.
        finally:
            os.close(fd) 

def main():
        '''
        Run code specified by data received over pipe
        '''
        assert is_forking(sys.argv)

        handle = int(sys.argv[-1])
        fd = msvcrt.open_osfhandle(handle, os.O_RDONLY)
        from_parent = os.fdopen(fd, 'rb')

        process.current_process()._inheriting = True
        preparation_data = load(from_parent)
        prepare(preparation_data)
        self = load(from_parent)
        process.current_process()._inheriting = False

        from_parent.close()

        exitcode = self._bootstrap()
        exit(exitcode) 

def test_write(self):
        test_filename = "tmp.write.test"
        
        # trivial write
        fd = os.open(test_filename, flags)
        self.assertEqual(os.write(fd, "42"), 2)
        os.close(fd)
        os.unlink(test_filename)

        # write to closed file
        fd = os.open(test_filename, flags)
        os.close(fd)
        self.assertRaisesMessage(OSError, "[Errno 9] Bad file descriptor", os.write, fd, "42")
        os.unlink(test_filename)
        
        # write to file with wrong permissions
        fd = os.open(test_filename, os.O_CREAT | os.O_TRUNC | os.O_RDONLY)
        self.assertRaisesMessage(OSError, "[Errno -2146232800] Can not write to " + test_filename,  os.write, fd, "42")
        os.close(fd)
        os.unlink(test_filename) 

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 test_get_secret(self):
        fd_mock = mock.mock_open()
        open_mock = mock.Mock()
        secret_id = uuidutils.generate_uuid()
        # Attempt to retrieve the secret
        with mock.patch('os.open', open_mock), mock.patch.object(
                os, 'fdopen', fd_mock):
            local_cert_mgr.LocalCertManager.get_secret(None, secret_id)

        # Verify the correct files were opened
        flags = os.O_RDONLY
        open_mock.assert_called_once_with('/tmp/{0}.crt'.format(secret_id),
                                          flags)

        # Test failure path
        with mock.patch('os.open', open_mock), mock.patch.object(
                os, 'fdopen', fd_mock) as mock_open:
            mock_open.side_effect = IOError
            self.assertRaises(exceptions.CertificateRetrievalException,
                              local_cert_mgr.LocalCertManager.get_secret,
                              None, secret_id) 

def _readflags(sequential, direct):
    flags = os.O_RDONLY
    try:
        flags |= os.O_BINARY
        if sequential is not None:
            flags |= os.O_SEQUENTIAL if sequential else os.O_RANDOM

    except AttributeError:
        pass

    try:
        if direct:
            flags |= os.O_DIRECT
            read = directio.read
        else:
            raise AttributeError

    except AttributeError:
        read = os.read

    return read, flags 

def _getTerminalSize_linux():
    def ioctl_GWINSZ(fd):
        try:
            import fcntl, termios, struct, os
            cr = struct.unpack('hh', fcntl.ioctl(fd, termios.TIOCGWINSZ,'1234'))
        except:
            return None
        return cr
    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 = (env['LINES'], env['COLUMNS'])
        except:
            return None
    return int(cr[1]), int(cr[0]) 

def get_terminal_size():
    """Returns a tuple (x, y) representing the width(x) and the height(x)
    in characters of the terminal window."""
    def ioctl_GWINSZ(fd):
        try:
            import fcntl
            import termios
            import struct
            cr = struct.unpack(
                'hh',
                fcntl.ioctl(fd, termios.TIOCGWINSZ, '1234')
            )
        except:
            return None
        if cr == (0, 0):
            return None
        return cr
    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:
        cr = (os.environ.get('LINES', 25), os.environ.get('COLUMNS', 80))
    return int(cr[1]), int(cr[0]) 

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 _stat(fn):
        fd = _os.open(fn, _os.O_RDONLY)
        _os.close(fd) 

def _get_cert(self, cert_id):
        fd_mock = mock.mock_open()
        fd_mock.side_effect = [
            mock.mock_open(read_data=self.certificate).return_value,
            mock.mock_open(read_data=self.private_key).return_value,
            mock.mock_open(read_data=self.intermediates).return_value,
            mock.mock_open(read_data=self.private_key_passphrase).return_value
        ]
        open_mock = mock.Mock()
        # Attempt to retrieve the cert
        with mock.patch('os.open', open_mock), mock.patch.object(
                os, 'fdopen', fd_mock):
            data = local_cert_mgr.LocalCertManager.get_cert(None, cert_id)

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

        # The returned data should be a Cert object
        self.assertIsInstance(data, cert.Cert)

        return data 

def get_secret(context, secret_ref):
        """Retrieves a secret payload by reference.

        :param context: Ignored in this implementation
        :param secret_ref: The secret reference ID

        :return: The secret payload
        :raises CertificateStorageException: if secret retrieval fails
        """
        LOG.info("Loading secret %s from the local filesystem.", secret_ref)

        filename_base = os.path.join(CONF.certificates.storage_path,
                                     secret_ref)

        filename_secret = "{0}.crt".format(filename_base)

        secret_data = None

        flags = os.O_RDONLY
        try:
            with os.fdopen(os.open(filename_secret, flags)) as secret_file:
                secret_data = secret_file.read()
        except IOError:
            LOG.error("Failed to read secret for %s.", secret_ref)
            raise exceptions.CertificateRetrievalException(ref=secret_ref)

        return secret_data 

def file_flags_to_mode(flags):
    """Convert file's open() flags into a readable string.
    Used by Process.open_files().
    """
    modes_map = {os.O_RDONLY: 'r', os.O_WRONLY: 'w', os.O_RDWR: 'w+'}
    mode = modes_map[flags & (os.O_RDONLY | os.O_WRONLY | os.O_RDWR)]
    if flags & os.O_APPEND:
        mode = mode.replace('w', 'a', 1)
    mode = mode.replace('w+', 'r+')
    # possible values: r, w, a, r+, a+
    return mode 

def get_terminal_size():
        """
        Returns a tuple (x, y) representing the width(x) and the height(y)
        in characters of the terminal window.
        """
        def ioctl_GWINSZ(fd):
            try:
                import fcntl
                import termios
                import struct
                cr = struct.unpack_from(
                    'hh',
                    fcntl.ioctl(fd, termios.TIOCGWINSZ, '12345678')
                )
            except:
                return None
            if cr == (0, 0):
                return None
            return cr
        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:
            cr = (os.environ.get('LINES', 25), os.environ.get('COLUMNS', 80))
        return int(cr[1]), int(cr[0]) 

def get_path_uid(path):
    """
    Return path's uid.

    Does not follow symlinks:
        https://github.com/pypa/pip/pull/935#discussion_r5307003

    Placed this function in compat due to differences on AIX and
    Jython, that should eventually go away.

    :raises OSError: When path is a symlink or can't be read.
    """
    if hasattr(os, 'O_NOFOLLOW'):
        fd = os.open(path, os.O_RDONLY | os.O_NOFOLLOW)
        file_uid = os.fstat(fd).st_uid
        os.close(fd)
    else:  # AIX and Jython
        # WARNING: time of check vulnerability, but best we can do w/o NOFOLLOW
        if not os.path.islink(path):
            # older versions of Jython don't have `os.fstat`
            file_uid = os.stat(path).st_uid
        else:
            # raise OSError for parity with os.O_NOFOLLOW above
            raise OSError(
                "%s is a symlink; Will not return uid for symlinks" % path
            )
    return file_uid 

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 __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 recover_fds(self):
        """
        Helper function for reconnect to daemon/nohup process.
        """
        if self.r_pipe is None:
            self.recover_paths()
            self.w_pipe = os.open(self.w_path, os.O_WRONLY)
            self.r_pipe = os.open(self.r_path, os.O_RDONLY)
            self.stdin_pipe = os.open(self.stdin_path, os.O_WRONLY)
            self.stdout_pipe = os.open(self.stdout_path, os.O_RDONLY)
            self.stderr_pipe = os.open(self.stderr_path, os.O_RDONLY)
            self.msg = ms.Messenger(ms.StdIOWrapperIn(self.r_pipe),
                                    ms.StdIOWrapperOut(self.w_pipe)) 

def testUnclosedFDOnException(self):
        class MyException(Exception): pass
        class MyFileIO(_FileIO):
            def __setattr__(self, name, value):
                if name == "name":
                    raise MyException("blocked setting name")
                return super(MyFileIO, self).__setattr__(name, value)
        fd = os.open(__file__, os.O_RDONLY)
        self.assertRaises(MyException, MyFileIO, fd)
        os.close(fd)  # should not raise OSError(EBADF) 

def _get_terminal_size_linux():
    def ioctl_GWINSZ(fd):
        try:
            import fcntl
            import termios
            import struct
            cr = struct.unpack(
                'hh', fcntl.ioctl(fd, termios.TIOCGWINSZ, '1234'))
        except (struct.error, IOError):
            return None
        return cr
    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 OSError:
            pass
    if not cr or cr == (0, 0):
        try:
            from os import environ as env
            cr = (env['LINES'], env['COLUMNS'])
        except (ValueError, KeyError):
            return None
    return int(cr[1]), int(cr[0]) 

def test_fdopen_keeps_fd_open_on_errors(self):
        fd = os.open(test_support.TESTFN, os.O_RDONLY)
        self.assertRaises(OSError, posix.fdopen, fd, 'w')
        os.close(fd) # fd should not be closed. 

def test_fdopen_directory(self):
        try:
            fd = os.open('.', os.O_RDONLY)
            self.addCleanup(os.close, fd)
        except OSError as e:
            self.assertEqual(e.errno, errno.EACCES)
            self.skipTest("system cannot open directories")
        with self.assertRaises(IOError) as cm:
            os.fdopen(fd, 'r')
        self.assertEqual(cm.exception.errno, errno.EISDIR) 

def fdopen_helper(self, *args):
        fd = os.open(test_support.TESTFN, os.O_RDONLY)
        fp2 = posix.fdopen(fd, *args)
        fp2.close() 

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)