This file is indexed.

/usr/lib/python3/dist-packages/serial/serialutil.py is in python3-serial 3.2.1-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
#! python
#
# Base class and support functions used by various backends.
#
# This file is part of pySerial. https://github.com/pyserial/pyserial
# (C) 2001-2016 Chris Liechti <cliechti@gmx.net>
#
# SPDX-License-Identifier:    BSD-3-Clause

import io
import time

# ``memoryview`` was introduced in Python 2.7 and ``bytes(some_memoryview)``
# isn't returning the contents (very unfortunate). Therefore we need special
# cases and test for it. Ensure that there is a ``memoryview`` object for older
# Python versions. This is easier than making every test dependent on its
# existence.
try:
    memoryview
except (NameError, AttributeError):
    # implementation does not matter as we do not really use it.
    # it just must not inherit from something else we might care for.
    class memoryview(object):   # pylint: disable=redefined-builtin,invalid-name
        pass

try:
    unicode
except (NameError, AttributeError):
    unicode = str       # for Python 3, pylint: disable=redefined-builtin,invalid-name

try:
    basestring
except (NameError, AttributeError):
    basestring = (str,)    # for Python 3, pylint: disable=redefined-builtin,invalid-name


# "for byte in data" fails for python3 as it returns ints instead of bytes
def iterbytes(b):
    """Iterate over bytes, returning bytes instead of ints (python3)"""
    if isinstance(b, memoryview):
        b = b.tobytes()
    i = 0
    while True:
        a = b[i:i + 1]
        i += 1
        if a:
            yield a
        else:
            break


# all Python versions prior 3.x convert ``str([17])`` to '[17]' instead of '\x11'
# so a simple ``bytes(sequence)`` doesn't work for all versions
def to_bytes(seq):
    """convert a sequence to a bytes type"""
    if isinstance(seq, bytes):
        return seq
    elif isinstance(seq, bytearray):
        return bytes(seq)
    elif isinstance(seq, memoryview):
        return seq.tobytes()
    elif isinstance(seq, unicode):
        raise TypeError('unicode strings are not supported, please encode to bytes: {!r}'.format(seq))
    else:
        # handle list of integers and bytes (one or more items) for Python 2 and 3
        return bytes(bytearray(seq))


# create control bytes
XON = to_bytes([17])
XOFF = to_bytes([19])

CR = to_bytes([13])
LF = to_bytes([10])


PARITY_NONE, PARITY_EVEN, PARITY_ODD, PARITY_MARK, PARITY_SPACE = 'N', 'E', 'O', 'M', 'S'
STOPBITS_ONE, STOPBITS_ONE_POINT_FIVE, STOPBITS_TWO = (1, 1.5, 2)
FIVEBITS, SIXBITS, SEVENBITS, EIGHTBITS = (5, 6, 7, 8)

PARITY_NAMES = {
    PARITY_NONE: 'None',
    PARITY_EVEN: 'Even',
    PARITY_ODD: 'Odd',
    PARITY_MARK: 'Mark',
    PARITY_SPACE: 'Space',
}


class SerialException(IOError):
    """Base class for serial port related exceptions."""


class SerialTimeoutException(SerialException):
    """Write timeouts give an exception"""


writeTimeoutError = SerialTimeoutException('Write timeout')
portNotOpenError = SerialException('Attempting to use a port that is not open')


class Timeout(object):
    """\
    Abstraction for timeout operations. Using time.monotonic() if available
    or time.time() in all other cases.

    The class can also be initialized with 0 or None, in order to support
    non-blocking and fully blocking I/O operations. The attributes
    is_non_blocking and is_infinite are set accordingly.
    """
    if hasattr(time, 'monotonic'):
        # Timeout implementation with time.monotonic(). This function is only
        # supported by Python 3.3 and above. It returns a time in seconds
        # (float) just as time.time(), but is not affected by system clock
        # adjustments.
        TIME = time.monotonic
    else:
        # Timeout implementation with time.time(). This is compatible with all
        # Python versions but has issues if the clock is adjusted while the
        # timeout is running.
        TIME = time.time

    def __init__(self, duration):
        """Initialize a timeout with given duration"""
        self.is_infinite = (duration is None)
        self.is_non_blocking = (duration == 0)
        self.duration = duration
        if duration is not None:
            self.target_time = self.TIME() + duration
        else:
            self.target_time = None

    def expired(self):
        """Return a boolean, telling if the timeout has expired"""
        return self.target_time is not None and self.time_left() <= 0

    def time_left(self):
        """Return how many seconds are left until the timeout expires"""
        if self.is_non_blocking:
            return 0
        elif self.is_infinite:
            return None
        else:
            delta = self.target_time - self.TIME()
            if delta > self.duration:
                # clock jumped, recalculate
                self.target_time = self.TIME() + self.duration
                return self.duration
            else:
                return max(0, delta)

    def restart(self, duration):
        """\
        Restart a timeout, only supported if a timeout was already set up
        before.
        """
        self.duration = duration
        self.target_time = self.TIME() + duration


class SerialBase(io.RawIOBase):
    """\
    Serial port base class. Provides __init__ function and properties to
    get/set port settings.
    """

    # default values, may be overridden in subclasses that do not support all values
    BAUDRATES = (50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800,
                 9600, 19200, 38400, 57600, 115200, 230400, 460800, 500000,
                 576000, 921600, 1000000, 1152000, 1500000, 2000000, 2500000,
                 3000000, 3500000, 4000000)
    BYTESIZES = (FIVEBITS, SIXBITS, SEVENBITS, EIGHTBITS)
    PARITIES = (PARITY_NONE, PARITY_EVEN, PARITY_ODD, PARITY_MARK, PARITY_SPACE)
    STOPBITS = (STOPBITS_ONE, STOPBITS_ONE_POINT_FIVE, STOPBITS_TWO)

    def __init__(self,
                 port=None,
                 baudrate=9600,
                 bytesize=EIGHTBITS,
                 parity=PARITY_NONE,
                 stopbits=STOPBITS_ONE,
                 timeout=None,
                 xonxoff=False,
                 rtscts=False,
                 write_timeout=None,
                 dsrdtr=False,
                 inter_byte_timeout=None,
                 **kwargs):
        """\
        Initialize comm port object. If a "port" is given, then the port will be
        opened immediately. Otherwise a Serial port object in closed state
        is returned.
        """

        self.is_open = False
        self.portstr = None
        self.name = None
        # correct values are assigned below through properties
        self._port = None
        self._baudrate = None
        self._bytesize = None
        self._parity = None
        self._stopbits = None
        self._timeout = None
        self._write_timeout = None
        self._xonxoff = None
        self._rtscts = None
        self._dsrdtr = None
        self._inter_byte_timeout = None
        self._rs485_mode = None  # disabled by default
        self._rts_state = True
        self._dtr_state = True
        self._break_state = False

        # assign values using get/set methods using the properties feature
        self.port = port
        self.baudrate = baudrate
        self.bytesize = bytesize
        self.parity = parity
        self.stopbits = stopbits
        self.timeout = timeout
        self.write_timeout = write_timeout
        self.xonxoff = xonxoff
        self.rtscts = rtscts
        self.dsrdtr = dsrdtr
        self.inter_byte_timeout = inter_byte_timeout
        # watch for backward compatible kwargs
        if 'writeTimeout' in kwargs:
            self.write_timeout = kwargs.pop('writeTimeout')
        if 'interCharTimeout' in kwargs:
            self.inter_byte_timeout = kwargs.pop('interCharTimeout')
        if kwargs:
            raise ValueError('unexpected keyword arguments: {!r}'.format(kwargs))

        if port is not None:
            self.open()

    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -

    # to be implemented by subclasses:
    # def open(self):
    # def close(self):

    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -

    @property
    def port(self):
        """\
        Get the current port setting. The value that was passed on init or using
        setPort() is passed back.
        """
        return self._port

    @port.setter
    def port(self, port):
        """\
        Change the port.
        """
        if port is not None and not isinstance(port, basestring):
            raise ValueError('"port" must be None or a string, not {}'.format(type(port)))
        was_open = self.is_open
        if was_open:
            self.close()
        self.portstr = port
        self._port = port
        self.name = self.portstr
        if was_open:
            self.open()

    @property
    def baudrate(self):
        """Get the current baud rate setting."""
        return self._baudrate

    @baudrate.setter
    def baudrate(self, baudrate):
        """\
        Change baud rate. It raises a ValueError if the port is open and the
        baud rate is not possible. If the port is closed, then the value is
        accepted and the exception is raised when the port is opened.
        """
        try:
            b = int(baudrate)
        except TypeError:
            raise ValueError("Not a valid baudrate: {!r}".format(baudrate))
        else:
            if b < 0:
                raise ValueError("Not a valid baudrate: {!r}".format(baudrate))
            self._baudrate = b
            if self.is_open:
                self._reconfigure_port()

    @property
    def bytesize(self):
        """Get the current byte size setting."""
        return self._bytesize

    @bytesize.setter
    def bytesize(self, bytesize):
        """Change byte size."""
        if bytesize not in self.BYTESIZES:
            raise ValueError("Not a valid byte size: {!r}".format(bytesize))
        self._bytesize = bytesize
        if self.is_open:
            self._reconfigure_port()

    @property
    def parity(self):
        """Get the current parity setting."""
        return self._parity

    @parity.setter
    def parity(self, parity):
        """Change parity setting."""
        if parity not in self.PARITIES:
            raise ValueError("Not a valid parity: {!r}".format(parity))
        self._parity = parity
        if self.is_open:
            self._reconfigure_port()

    @property
    def stopbits(self):
        """Get the current stop bits setting."""
        return self._stopbits

    @stopbits.setter
    def stopbits(self, stopbits):
        """Change stop bits size."""
        if stopbits not in self.STOPBITS:
            raise ValueError("Not a valid stop bit size: {!r}".format(stopbits))
        self._stopbits = stopbits
        if self.is_open:
            self._reconfigure_port()

    @property
    def timeout(self):
        """Get the current timeout setting."""
        return self._timeout

    @timeout.setter
    def timeout(self, timeout):
        """Change timeout setting."""
        if timeout is not None:
            try:
                timeout + 1     # test if it's a number, will throw a TypeError if not...
            except TypeError:
                raise ValueError("Not a valid timeout: {!r}".format(timeout))
            if timeout < 0:
                raise ValueError("Not a valid timeout: {!r}".format(timeout))
        self._timeout = timeout
        if self.is_open:
            self._reconfigure_port()

    @property
    def write_timeout(self):
        """Get the current timeout setting."""
        return self._write_timeout

    @write_timeout.setter
    def write_timeout(self, timeout):
        """Change timeout setting."""
        if timeout is not None:
            if timeout < 0:
                raise ValueError("Not a valid timeout: {!r}".format(timeout))
            try:
                timeout + 1     # test if it's a number, will throw a TypeError if not...
            except TypeError:
                raise ValueError("Not a valid timeout: {!r}".format(timeout))

        self._write_timeout = timeout
        if self.is_open:
            self._reconfigure_port()

    @property
    def inter_byte_timeout(self):
        """Get the current inter-character timeout setting."""
        return self._inter_byte_timeout

    @inter_byte_timeout.setter
    def inter_byte_timeout(self, ic_timeout):
        """Change inter-byte timeout setting."""
        if ic_timeout is not None:
            if ic_timeout < 0:
                raise ValueError("Not a valid timeout: {!r}".format(ic_timeout))
            try:
                ic_timeout + 1     # test if it's a number, will throw a TypeError if not...
            except TypeError:
                raise ValueError("Not a valid timeout: {!r}".format(ic_timeout))

        self._inter_byte_timeout = ic_timeout
        if self.is_open:
            self._reconfigure_port()

    @property
    def xonxoff(self):
        """Get the current XON/XOFF setting."""
        return self._xonxoff

    @xonxoff.setter
    def xonxoff(self, xonxoff):
        """Change XON/XOFF setting."""
        self._xonxoff = xonxoff
        if self.is_open:
            self._reconfigure_port()

    @property
    def rtscts(self):
        """Get the current RTS/CTS flow control setting."""
        return self._rtscts

    @rtscts.setter
    def rtscts(self, rtscts):
        """Change RTS/CTS flow control setting."""
        self._rtscts = rtscts
        if self.is_open:
            self._reconfigure_port()

    @property
    def dsrdtr(self):
        """Get the current DSR/DTR flow control setting."""
        return self._dsrdtr

    @dsrdtr.setter
    def dsrdtr(self, dsrdtr=None):
        """Change DsrDtr flow control setting."""
        if dsrdtr is None:
            # if not set, keep backwards compatibility and follow rtscts setting
            self._dsrdtr = self._rtscts
        else:
            # if defined independently, follow its value
            self._dsrdtr = dsrdtr
        if self.is_open:
            self._reconfigure_port()

    @property
    def rts(self):
        return self._rts_state

    @rts.setter
    def rts(self, value):
        self._rts_state = value
        if self.is_open:
            self._update_rts_state()

    @property
    def dtr(self):
        return self._dtr_state

    @dtr.setter
    def dtr(self, value):
        self._dtr_state = value
        if self.is_open:
            self._update_dtr_state()

    @property
    def break_condition(self):
        return self._break_state

    @break_condition.setter
    def break_condition(self, value):
        self._break_state = value
        if self.is_open:
            self._update_break_state()

    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -
    # functions useful for RS-485 adapters

    @property
    def rs485_mode(self):
        """\
        Enable RS485 mode and apply new settings, set to None to disable.
        See serial.rs485.RS485Settings for more info about the value.
        """
        return self._rs485_mode

    @rs485_mode.setter
    def rs485_mode(self, rs485_settings):
        self._rs485_mode = rs485_settings
        if self.is_open:
            self._reconfigure_port()

    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -

    _SAVED_SETTINGS = ('baudrate', 'bytesize', 'parity', 'stopbits', 'xonxoff',
                       'dsrdtr', 'rtscts', 'timeout', 'write_timeout',
                       'inter_byte_timeout')

    def get_settings(self):
        """\
        Get current port settings as a dictionary. For use with
        apply_settings().
        """
        return dict([(key, getattr(self, '_' + key)) for key in self._SAVED_SETTINGS])

    def apply_settings(self, d):
        """\
        Apply stored settings from a dictionary returned from
        get_settings(). It's allowed to delete keys from the dictionary. These
        values will simply left unchanged.
        """
        for key in self._SAVED_SETTINGS:
            if key in d and d[key] != getattr(self, '_' + key):   # check against internal "_" value
                setattr(self, key, d[key])          # set non "_" value to use properties write function

    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -

    def __repr__(self):
        """String representation of the current port settings and its state."""
        return '{name}<id=0x{id:x}, open={p.is_open}>(port={p.portstr!r}, ' \
               'baudrate={p.baudrate!r}, bytesize={p.bytesize!r}, parity={p.parity!r}, ' \
               'stopbits={p.stopbits!r}, timeout={p.timeout!r}, xonxoff={p.xonxoff!r}, ' \
               'rtscts={p.rtscts!r}, dsrdtr={p.dsrdtr!r})'.format(
                   name=self.__class__.__name__, id=id(self), p=self)

    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -
    # compatibility with io library
    # pylint: disable=invalid-name,missing-docstring

    def readable(self):
        return True

    def writable(self):
        return True

    def seekable(self):
        return False

    def readinto(self, b):
        data = self.read(len(b))
        n = len(data)
        try:
            b[:n] = data
        except TypeError as err:
            import array
            if not isinstance(b, array.array):
                raise err
            b[:n] = array.array('b', data)
        return n

    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -
    # context manager

    def __enter__(self):
        return self

    def __exit__(self, *args, **kwargs):
        self.close()

    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -

    def send_break(self, duration=0.25):
        """\
        Send break condition. Timed, returns to idle state after given
        duration.
        """
        if not self.is_open:
            raise portNotOpenError
        self.break_condition = True
        time.sleep(duration)
        self.break_condition = False

    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -
    # backwards compatibility / deprecated functions

    def flushInput(self):
        self.reset_input_buffer()

    def flushOutput(self):
        self.reset_output_buffer()

    def inWaiting(self):
        return self.in_waiting

    def sendBreak(self, duration=0.25):
        self.send_break(duration)

    def setRTS(self, value=1):
        self.rts = value

    def setDTR(self, value=1):
        self.dtr = value

    def getCTS(self):
        return self.cts

    def getDSR(self):
        return self.dsr

    def getRI(self):
        return self.ri

    def getCD(self):
        return self.cd

    def setPort(self, port):
        self.port = port

    @property
    def writeTimeout(self):
        return self.write_timeout

    @writeTimeout.setter
    def writeTimeout(self, timeout):
        self.write_timeout = timeout

    @property
    def interCharTimeout(self):
        return self.inter_byte_timeout

    @interCharTimeout.setter
    def interCharTimeout(self, interCharTimeout):
        self.inter_byte_timeout = interCharTimeout

    def getSettingsDict(self):
        return self.get_settings()

    def applySettingsDict(self, d):
        self.apply_settings(d)

    def isOpen(self):
        return self.is_open

    #  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -
    # additional functionality

    def read_all(self):
        """\
        Read all bytes currently available in the buffer of the OS.
        """
        return self.read(self.in_waiting)

    def read_until(self, terminator=LF, size=None):
        """\
        Read until a termination sequence is found ('\n' by default), the size
        is exceeded or until timeout occurs.
        """
        lenterm = len(terminator)
        line = bytearray()
        while True:
            c = self.read(1)
            if c:
                line += c
                if line[-lenterm:] == terminator:
                    break
                if size is not None and len(line) >= size:
                    break
            else:
                break
        return bytes(line)

    def iread_until(self, *args, **kwargs):
        """\
        Read lines, implemented as generator. It will raise StopIteration on
        timeout (empty read).
        """
        while True:
            line = self.read_until(*args, **kwargs)
            if not line:
                break
            yield line


#  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -  -
if __name__ == '__main__':
    import sys
    s = SerialBase()
    sys.stdout.write('port name:  {}\n'.format(s.name))
    sys.stdout.write('baud rates: {}\n'.format(s.BAUDRATES))
    sys.stdout.write('byte sizes: {}\n'.format(s.BYTESIZES))
    sys.stdout.write('parities:   {}\n'.format(s.PARITIES))
    sys.stdout.write('stop bits:  {}\n'.format(s.STOPBITS))
    sys.stdout.write('{}\n'.format(s))