Python msvcrt.get_osfhandle() Examples

def _make_non_blocking(file_obj):
    """make file object non-blocking
    Windows doesn't have the fcntl module, but someone on
    stack overflow supplied this code as an answer, and it works
    http://stackoverflow.com/a/34504971/2893090"""

    if USING_WINDOWS:
        LPDWORD = POINTER(DWORD)
        PIPE_NOWAIT = wintypes.DWORD(0x00000001)

        SetNamedPipeHandleState = windll.kernel32.SetNamedPipeHandleState
        SetNamedPipeHandleState.argtypes = [HANDLE, LPDWORD, LPDWORD, LPDWORD]
        SetNamedPipeHandleState.restype = BOOL

        h = msvcrt.get_osfhandle(file_obj.fileno())

        res = windll.kernel32.SetNamedPipeHandleState(h, byref(PIPE_NOWAIT), None, None)
        if res == 0:
            raise ValueError(WinError())

    else:
        # Set the file status flag (F_SETFL) on the pipes to be non-blocking
        # so we can attempt to read from a pipe with no new data without locking
        # the program up
        fcntl.fcntl(file_obj, fcntl.F_SETFL, os.O_NONBLOCK) 

def isatty():
    if isatty.no_tty:
        return False
    f = sys.stdout
    if f.isatty():
        return True
    if not iswindows:
        return False
    # Check for a cygwin ssh pipe
    buf = ctypes.create_string_buffer(1024)
    h = msvcrt.get_osfhandle(f.fileno())
    if get_file_type(h) != 3:
        return False
    ret = get_file_info_by_handle(h, 2, buf, ctypes.sizeof(buf))
    if not ret:
        raise ctypes.WinError()
    data = buf.raw
    name = data[4:].decode('utf-16').rstrip(u'\0')
    parts = name.split('-')
    return parts[0] == r'\cygwin' and parts[2].startswith('pty') and parts[4] == 'master' 

def test_fd_transfer(self):
        if self.TYPE != 'processes':
            self.skipTest("only makes sense with processes")
        conn, child_conn = self.Pipe(duplex=True)

        p = self.Process(target=self._writefd, args=(child_conn, b"foo"))
        p.daemon = True
        p.start()
        self.addCleanup(test.support.unlink, test.support.TESTFN)
        with open(test.support.TESTFN, "wb") as f:
            fd = f.fileno()
            if msvcrt:
                fd = msvcrt.get_osfhandle(fd)
            reduction.send_handle(conn, fd, p.pid)
        p.join()
        with open(test.support.TESTFN, "rb") as f:
            self.assertEqual(f.read(), b"foo") 

def test_fd_transfer(self):
        if self.TYPE != 'processes':
            self.skipTest("only makes sense with processes")
        conn, child_conn = self.Pipe(duplex=True)

        p = self.Process(target=self._writefd, args=(child_conn, b"foo"))
        p.daemon = True
        p.start()
        with open(test_support.TESTFN, "wb") as f:
            fd = f.fileno()
            if msvcrt:
                fd = msvcrt.get_osfhandle(fd)
            reduction.send_handle(conn, fd, p.pid)
        p.join()
        with open(test_support.TESTFN, "rb") as f:
            self.assertEqual(f.read(), b"foo") 

def test_fd_transfer(self):
        if self.TYPE != 'processes':
            self.skipTest("only makes sense with processes")
        conn, child_conn = self.Pipe(duplex=True)

        p = self.Process(target=self._writefd, args=(child_conn, b"foo"))
        p.daemon = True
        p.start()
        with open(test_support.TESTFN, "wb") as f:
            fd = f.fileno()
            if msvcrt:
                fd = msvcrt.get_osfhandle(fd)
            reduction.send_handle(conn, fd, p.pid)
        p.join()
        with open(test_support.TESTFN, "rb") as f:
            self.assertEqual(f.read(), b"foo") 

def sendfile(self, sock, file, offset, count):
        self._register_with_iocp(sock)
        ov = _overlapped.Overlapped(NULL)
        offset_low = offset & 0xffff_ffff
        offset_high = (offset >> 32) & 0xffff_ffff
        ov.TransmitFile(sock.fileno(),
                        msvcrt.get_osfhandle(file.fileno()),
                        offset_low, offset_high,
                        count, 0, 0)

        def finish_sendfile(trans, key, ov):
            try:
                return ov.getresult()
            except OSError as exc:
                if exc.winerror in (_overlapped.ERROR_NETNAME_DELETED,
                                    _overlapped.ERROR_OPERATION_ABORTED):
                    raise ConnectionResetError(*exc.args)
                else:
                    raise
        return self._register(ov, sock, finish_sendfile) 

def _recv(self, which, maxsize):
            conn, maxsize = self.get_conn_maxsize(which, maxsize)
            if conn is None:
                return None

            try:
                x = msvcrt.get_osfhandle(conn.fileno())
                (read, nAvail, nMessage) = PeekNamedPipe(x, 0)
                if maxsize < nAvail:
                    nAvail = maxsize
                if nAvail > 0:
                    (errCode, read) = ReadFile(x, nAvail, None)
            except ValueError:
                return self._close(which)
            except (subprocess.pywintypes.error, Exception) as why:
                if why[0] in (109, errno.ESHUTDOWN):
                    return self._close(which)
                raise

            #if self.universal_newlines:
            #    read = self._translate_newlines(read)
            return read 

def _recv(self, which, maxsize):
            conn, maxsize = self.get_conn_maxsize(which, maxsize)
            if conn is None:
                return None

            try:
                x = msvcrt.get_osfhandle(conn.fileno())
                (read, nAvail, nMessage) = PeekNamedPipe(x, 0)
                if maxsize < nAvail:
                    nAvail = maxsize
                if nAvail > 0:
                    (errCode, read) = ReadFile(x, nAvail, None)
            except (ValueError, NameError):
                return self._close(which)
            except (subprocess.pywintypes.error, Exception), why:
                if why[0] in (109, errno.ESHUTDOWN):
                    return self._close(which)
                raise 

def _recv(self, which, maxsize):
            conn, maxsize = self.get_conn_maxsize(which, maxsize)
            if conn is None:
                return None

            try:
                x = msvcrt.get_osfhandle(conn.fileno())
                (read, nAvail, nMessage) = PeekNamedPipe(x, 0)
                if maxsize < nAvail:
                    nAvail = maxsize
                if nAvail > 0:
                    (errCode, read) = ReadFile(x, nAvail, None)
            except (ValueError, NameError):
                return self._close(which)
            except (subprocess.pywintypes.error, Exception), why:
                if why[0] in (109, errno.ESHUTDOWN):
                    return self._close(which)
                raise 

def test_fd_transfer(self):
        if self.TYPE != 'processes':
            self.skipTest("only makes sense with processes")
        conn, child_conn = self.Pipe(duplex=True)

        p = self.Process(target=self._writefd, args=(child_conn, b"foo"))
        p.daemon = True
        p.start()
        with open(test_support.TESTFN, "wb") as f:
            fd = f.fileno()
            if msvcrt:
                fd = msvcrt.get_osfhandle(fd)
            reduction.send_handle(conn, fd, p.pid)
        p.join()
        with open(test_support.TESTFN, "rb") as f:
            self.assertEqual(f.read(), b"foo") 

def _recv(self, which, maxsize):
            conn, maxsize = self.get_conn_maxsize(which, maxsize)
            if conn is None:
                return None

            try:
                x = msvcrt.get_osfhandle(conn.fileno())
                (read, nAvail, nMessage) = PeekNamedPipe(x, 0)
                if maxsize < nAvail:
                    nAvail = maxsize
                if nAvail > 0:
                    (errCode, read) = ReadFile(x, nAvail, None)
            except ValueError:
                return self._close(which)
            except (subprocess.pywintypes.error, Exception) as why:
                if why[0] in (109, errno.ESHUTDOWN):
                    return self._close(which)
                raise

            #if self.universal_newlines:
            #    read = self._translate_newlines(read)
            return read 

def test_fd_transfer(self):
        if self.TYPE != 'processes':
            self.skipTest("only makes sense with processes")
        conn, child_conn = self.Pipe(duplex=True)

        p = self.Process(target=self._writefd, args=(child_conn, b"foo"))
        p.daemon = True
        p.start()
        self.addCleanup(support.unlink, support.TESTFN)
        with open(support.TESTFN, "wb") as f:
            fd = f.fileno()
            if msvcrt:
                fd = msvcrt.get_osfhandle(fd)
            reduction.send_handle(conn, fd, p.pid)
        p.join()
        with open(support.TESTFN, "rb") as f:
            self.assertEqual(f.read(), b"foo") 

def test_fd_transfer(self):
        if self.TYPE != 'processes':
            self.skipTest("only makes sense with processes")
        conn, child_conn = self.Pipe(duplex=True)

        p = self.Process(target=self._writefd, args=(child_conn, b"foo"))
        p.daemon = True
        p.start()
        self.addCleanup(test.support.unlink, test.support.TESTFN)
        with open(test.support.TESTFN, "wb") as f:
            fd = f.fileno()
            if msvcrt:
                fd = msvcrt.get_osfhandle(fd)
            reduction.send_handle(conn, fd, p.pid)
        p.join()
        with open(test.support.TESTFN, "rb") as f:
            self.assertEqual(f.read(), b"foo") 

def run(cmd, mSec=None, stdin=None, stdout=None, stderr=None, **kw):
    """
    Run cmd as a child process and return exit code.
    mSec:  terminate cmd after specified number of milliseconds
    stdin, stdout, stderr:
           file objects for child I/O (use hStdin etc. to attach
           handles instead of files); default is caller's stdin,
           stdout & stderr;
    kw:    see Process.__init__ for more keyword options
    """
    if stdin is not None:
        kw['hStdin'] = msvcrt.get_osfhandle(stdin.fileno())
    if stdout is not None:
        kw['hStdout'] = msvcrt.get_osfhandle(stdout.fileno())
    if stderr is not None:
        kw['hStderr'] = msvcrt.get_osfhandle(stderr.fileno())
    child = Process(cmd, **kw)
    if child.wait(mSec) != win32event.WAIT_OBJECT_0:
        child.kill()
        raise WindowsError('process timeout exceeded')
    return child.exitCode() 

def send(self, input):
            input = to_bytes(input)
            if not self.stdin:
                return None

            try:
                x = msvcrt.get_osfhandle(self.stdin.fileno())
                (errCode, written) = WriteFile(x, input)
            except ValueError:
                return self._close('stdin')
            except (subprocess.pywintypes.error, Exception) as why:
                if why.args[0] in (109, errno.ESHUTDOWN):
                    return self._close('stdin')
                raise

            return written 

def _recv(self, which, maxsize):
            conn, maxsize = self.get_conn_maxsize(which, maxsize)
            if conn is None:
                return None

            try:
                x = msvcrt.get_osfhandle(conn.fileno())
                (read, nAvail, nMessage) = PeekNamedPipe(x, 0)
                if maxsize < nAvail:
                    nAvail = maxsize
                if nAvail > 0:
                    (errCode, read) = ReadFile(x, nAvail, None)
            except ValueError:
                return self._close(which)
            except (subprocess.pywintypes.error, Exception) as why:
                if why.args[0] in (109, errno.ESHUTDOWN):
                    return self._close(which)
                raise

            # if self.universal_newlines:
            #    read = self._translate_newlines(read)
            return read 

def _recv(self, which, maxsize):
            conn, maxsize = self.get_conn_maxsize(which, maxsize)
            if conn is None:
                return None

            try:
                x = msvcrt.get_osfhandle(conn.fileno())
                (read, nAvail, nMessage) = PeekNamedPipe(x, 0)
                if maxsize < nAvail:
                    nAvail = maxsize
                if nAvail > 0:
                    (errCode, read) = ReadFile(x, nAvail, None)
            except ValueError:
                return self._close(which)
            except (subprocess.pywintypes.error, Exception), why:
                if why[0] in (109, errno.ESHUTDOWN):
                    return self._close(which)
                raise

            #if self.universal_newlines:
            #    read = self._translate_newlines(read) 

def send(self, input):
            if not self.stdin:
                return None

            try:
                x = msvcrt.get_osfhandle(self.stdin.fileno())
                (errCode, written) = WriteFile(x, input)
            except ValueError:
                return self._close('stdin')
            except (subprocess.pywintypes.error, Exception), why:
                if why[0] in (109, errno.ESHUTDOWN):
                    return self._close('stdin')
                raise 

def _scons_open(*args, **kw):
        fp = _builtin_open(*args, **kw)
        win32api.SetHandleInformation(msvcrt.get_osfhandle(fp.fileno()),
                                      win32con.HANDLE_FLAG_INHERIT,
                                      0)
        return fp 

def __init__(self, *args, **kw):
            _builtin_file.__init__(self, *args, **kw)
            win32api.SetHandleInformation(msvcrt.get_osfhandle(self.fileno()),
                win32con.HANDLE_FLAG_INHERIT, 0) 

def __init__(self, recognize_paste: bool = True) -> None:
        self._fdcon = None
        self.recognize_paste = recognize_paste

        # When stdin is a tty, use that handle, otherwise, create a handle from
        # CONIN$.
        self.handle: HANDLE
        if sys.stdin.isatty():
            self.handle = HANDLE(windll.kernel32.GetStdHandle(STD_INPUT_HANDLE))
        else:
            self._fdcon = os.open("CONIN$", os.O_RDWR | os.O_BINARY)
            self.handle = HANDLE(msvcrt.get_osfhandle(self._fdcon)) 

def __init__(self, process_obj):
            # create pipe for communication with child
            rfd, wfd = os.pipe()

            # get handle for read end of the pipe and make it inheritable
            rhandle = duplicate(msvcrt.get_osfhandle(rfd), inheritable=True)
            os.close(rfd)

            # start process
            cmd = get_command_line() + [rhandle]
            cmd = ' '.join('"%s"' % x for x in cmd)
            hp, ht, pid, tid = _subprocess.CreateProcess(
                _python_exe, cmd, None, None, 1, 0, None, None, None
                )
            ht.Close()
            close(rhandle)

            # set attributes of self
            self.pid = pid
            self.returncode = None
            self._handle = hp

            # send information to child
            prep_data = get_preparation_data(process_obj._name)
            to_child = os.fdopen(wfd, 'wb')
            Popen._tls.process_handle = int(hp)
            try:
                dump(prep_data, to_child, HIGHEST_PROTOCOL)
                dump(process_obj, to_child, HIGHEST_PROTOCOL)
            finally:
                del Popen._tls.process_handle
                to_child.close() 

def lock(file, flags):
        hfile = msvcrt.get_osfhandle(file.fileno())
        overlapped = OVERLAPPED()
        LockFileEx(hfile, flags, 0, 0, 0xFFFF0000, ctypes.byref(overlapped)) 

def unlock(file):
        hfile = msvcrt.get_osfhandle(file.fileno())
        overlapped = OVERLAPPED()
        UnlockFileEx(hfile, 0, 0, 0xFFFF0000, ctypes.byref(overlapped)) 

def get_handle(fd):
        return msvcrt.get_osfhandle(fd) 

def _lock_file(f, exclusive):
        overlapped = OVERLAPPED()
        overlapped.Offset = 0
        overlapped.OffsetHigh = 0
        overlapped.hEvent = 0
        f._lock_file_overlapped_p = ctypes.pointer(overlapped)
        handle = msvcrt.get_osfhandle(f.fileno())
        if not LockFileEx(handle, 0x2 if exclusive else 0x0, 0,
                          whole_low, whole_high, f._lock_file_overlapped_p):
            raise OSError('Locking file failed: %r' % ctypes.FormatError()) 

def send(self, input):
            if not self.stdin:
                return None

            try:
                x = msvcrt.get_osfhandle(self.stdin.fileno())
                (errCode, written) = WriteFile(x, input)
            except ValueError:
                return self._close('stdin')
            except (subprocess.pywintypes.error, Exception), why:
                if why[0] in (109, errno.ESHUTDOWN):
                    return self._close('stdin')
                raise 

def testInvalidFd(self):
        self.assertRaises(ValueError, self.FileIO, -10)
        self.assertRaises(OSError, self.FileIO, make_bad_fd())
        if sys.platform == 'win32':
            import msvcrt
            self.assertRaises(OSError, msvcrt.get_osfhandle, make_bad_fd()) 

def _unlock_file(f):
        assert f._lock_file_overlapped_p
        handle = msvcrt.get_osfhandle(f.fileno())
        if not UnlockFileEx(handle, 0,
                            whole_low, whole_high, f._lock_file_overlapped_p):
            raise OSError('Unlocking file failed: %r' % ctypes.FormatError()) 

def _unlock_file(f):
        assert f._lock_file_overlapped_p
        handle = msvcrt.get_osfhandle(f.fileno())
        if not UnlockFileEx(handle, 0,
                            whole_low, whole_high, f._lock_file_overlapped_p):
            raise OSError('Unlocking file failed: %r' % ctypes.FormatError())