summaryrefslogtreecommitdiffstats
path: root/Lib/nntplib.py
blob: 16e7550f7963be7735aef5f6f907cf13ee5ed7c0 (plain)
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
"""An NNTP client class based on RFC 977: Network News Transfer Protocol.

Example:

>>> from nntplib import NNTP
>>> s = NNTP('news')
>>> resp, count, first, last, name = s.group('comp.lang.python')
>>> print 'Group', name, 'has', count, 'articles, range', first, 'to', last
Group comp.lang.python has 51 articles, range 5770 to 5821
>>> resp, subs = s.xhdr('subject', first + '-' + last)
>>> resp = s.quit()
>>>

Here 'resp' is the server response line.
Error responses are turned into exceptions.

To post an article from a file:
>>> f = open(filename, 'r') # file containing article, including header
>>> resp = s.post(f)
>>>

For descriptions of all methods, read the comments in the code below.
Note that all arguments and return values representing article numbers
are strings, not numbers, since they are rarely used for calculations.
"""

# RFC 977 by Brian Kantor and Phil Lapsley.
# xover, xgtitle, xpath, date methods by Kevan Heydon


# Imports
import re
import socket

__all__ = ["NNTP","NNTPReplyError","NNTPTemporaryError",
           "NNTPPermanentError","NNTPProtocolError","NNTPDataError",
           "error_reply","error_temp","error_perm","error_proto",
           "error_data",]

# Exceptions raised when an error or invalid response is received
class NNTPError(Exception):
    """Base class for all nntplib exceptions"""
    def __init__(self, *args):
        apply(Exception.__init__, (self,)+args)
        try:
            self.response = args[0]
        except IndexError:
            self.response = 'No response given'

class NNTPReplyError(NNTPError):
    """Unexpected [123]xx reply"""
    pass

class NNTPTemporaryError(NNTPError):
    """4xx errors"""
    pass

class NNTPPermanentError(NNTPError):
    """5xx errors"""
    pass

class NNTPProtocolError(NNTPError):
    """Response does not begin with [1-5]"""
    pass

class NNTPDataError(NNTPError):
    """Error in response data"""
    pass

# for backwards compatibility
error_reply = NNTPReplyError
error_temp = NNTPTemporaryError
error_perm = NNTPPermanentError
error_proto = NNTPProtocolError
error_data = NNTPDataError



# Standard port used by NNTP servers
NNTP_PORT = 119


# Response numbers that are followed by additional text (e.g. article)
LONGRESP = ['100', '215', '220', '221', '222', '224', '230', '231', '282']


# Line terminators (we always output CRLF, but accept any of CRLF, CR, LF)
CRLF = '\r\n'



# The class itself
class NNTP:
    def __init__(self, host, port=NNTP_PORT, user=None, password=None,
                 readermode=None):
        """Initialize an instance.  Arguments:
        - host: hostname to connect to
        - port: port to connect to (default the standard NNTP port)
        - user: username to authenticate with
        - password: password to use with username
        - readermode: if true, send 'mode reader' command after
                      connecting.

        readermode is sometimes necessary if you are connecting to an
        NNTP server on the local machine and intend to call
        reader-specific comamnds, such as `group'.  If you get
        unexpected NNTPPermanentErrors, you might need to set
        readermode.
        """
        self.host = host
        self.port = port
        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.sock.connect((self.host, self.port))
        self.file = self.sock.makefile('rb')
        self.debugging = 0
        self.welcome = self.getresp()

        # 'mode reader' is sometimes necessary to enable 'reader' mode.
        # However, the order in which 'mode reader' and 'authinfo' need to
        # arrive differs between some NNTP servers. Try to send
        # 'mode reader', and if it fails with an authorization failed
        # error, try again after sending authinfo.
        readermode_afterauth = 0
        if readermode:
            try:
                self.welcome = self.shortcmd('mode reader')
            except NNTPPermanentError:
                # error 500, probably 'not implemented'
                pass
            except NNTPTemporaryError, e:
                if user and e.response[:3] == '480':
                    # Need authorization before 'mode reader'
                    readermode_afterauth = 1
                else:
                    raise
        # If no login/password was specified, try to get them from ~/.netrc
        # Presume that if .netc has an entry, NNRP authentication is required.
        try:
            if not user:
                import netrc
                credentials = netrc.netrc()
                auth = credentials.authenticators(host)
                if auth:
                    user = auth[0]
                    password = auth[2]
        except IOError:
            pass
        # Perform NNRP authentication if needed.
        if user:
            resp = self.shortcmd('authinfo user '+user)
            if resp[:3] == '381':
                if not password:
                    raise NNTPReplyError(resp)
                else:
                    resp = self.shortcmd(
                            'authinfo pass '+password)
                    if resp[:3] != '281':
                        raise NNTPPermanentError(resp)
            if readermode_afterauth:
                try:
                    self.welcome = self.shortcmd('mode reader')
                except NNTPPermanentError:
                    # error 500, probably 'not implemented'
                    pass


    # Get the welcome message from the server
    # (this is read and squirreled away by __init__()).
    # If the response code is 200, posting is allowed;
    # if it 201, posting is not allowed

    def getwelcome(self):
        """Get the welcome message from the server
        (this is read and squirreled away by __init__()).
        If the response code is 200, posting is allowed;
        if it 201, posting is not allowed."""

        if self.debugging: print '*welcome*', `self.welcome`
        return self.welcome

    def set_debuglevel(self, level):
        """Set the debugging level.  Argument 'level' means:
        0: no debugging output (default)
        1: print commands and responses but not body text etc.
        2: also print raw lines read and sent before stripping CR/LF"""

        self.debugging = level
    debug = set_debuglevel

    def putline(self, line):
        """Internal: send one line to the server, appending CRLF."""
        line = line + CRLF
        if self.debugging > 1: print '*put*', `line`
        self.sock.sendall(line)

    def putcmd(self, line):
        """Internal: send one command to the server (through putline())."""
        if self.debugging: print '*cmd*', `line`
        self.putline(line)

    def getline(self):
        """Internal: return one line from the server, stripping CRLF.
        Raise EOFError if the connection is closed."""
        line = self.file.readline()
        if self.debugging > 1:
            print '*get*', `line`
        if not line: raise EOFError
        if line[-2:] == CRLF: line = line[:-2]
        elif line[-1:] in CRLF: line = line[:-1]
        return line

    def getresp(self):
        """Internal: get a response from the server.
        Raise various errors if the response indicates an error."""
        resp = self.getline()
        if self.debugging: print '*resp*', `resp`
        c = resp[:1]
        if c == '4':
            raise NNTPTemporaryError(resp)
        if c == '5':
            raise NNTPPermanentError(resp)
        if c not in '123':
            raise NNTPProtocolError(resp)
        return resp

    def getlongresp(self, file=None):
        """Internal: get a response plus following text from the server.
        Raise various errors if the response indicates an error."""

        openedFile = None
        try:
            # If a string was passed then open a file with that name
            if isinstance(file, str):
                openedFile = file = open(file, "w")

            resp = self.getresp()
            if resp[:3] not in LONGRESP:
                raise NNTPReplyError(resp)
            list = []
            while 1:
                line = self.getline()
                if line == '.':
                    break
                if line[:2] == '..':
                    line = line[1:]
                if file:
                    file.write(line + "\n")
                else:
                    list.append(line)
        finally:
            # If this method created the file, then it must close it
            if openedFile:
                openedFile.close()

        return resp, list

    def shortcmd(self, line):
        """Internal: send a command and get the response."""
        self.putcmd(line)
        return self.getresp()

    def longcmd(self, line, file=None):
        """Internal: send a command and get the response plus following text."""
        self.putcmd(line)
        return self.getlongresp(file)

    def newgroups(self, date, time):
        """Process a NEWGROUPS command.  Arguments:
        - date: string 'yymmdd' indicating the date
        - time: string 'hhmmss' indicating the time
        Return:
        - resp: server response if successful
        - list: list of newsgroup names"""

        return self.longcmd('NEWGROUPS ' + date + ' ' + time)

    def newnews(self, group, date, time):
        """Process a NEWNEWS command.  Arguments:
        - group: group name or '*'
        - date: string 'yymmdd' indicating the date
        - time: string 'hhmmss' indicating the time
        Return:
        - resp: server response if successful
        - list: list of article ids"""

        cmd = 'NEWNEWS ' + group + ' ' + date + ' ' + time
        return self.longcmd(cmd)

    def list(self):
        """Process a LIST command.  Return:
        - resp: server response if successful
        - list: list of (group, last, first, flag) (strings)"""

        resp, list = self.longcmd('LIST')
        for i in range(len(list)):
            # Parse lines into "group last first flag"
            list[i] = tuple(list[i].split())
        return resp, list

    def group(self, name):
        """Process a GROUP command.  Argument:
        - group: the group name
        Returns:
        - resp: server response if successful
        - count: number of articles (string)
        - first: first article number (string)
        - last: last article number (string)
        - name: the group name"""

        resp = self.shortcmd('GROUP ' + name)
        if resp[:3] != '211':
            raise NNTPReplyError(resp)
        words = resp.split()
        count = first = last = 0
        n = len(words)
        if n > 1:
            count = words[1]
            if n > 2:
                first = words[2]
                if n > 3:
                    last = words[3]
                    if n > 4:
                        name = words[4].lower()
        return resp, count, first, last, name

    def help(self):
        """Process a HELP command.  Returns:
        - resp: server response if successful
        - list: list of strings"""

        return self.longcmd('HELP')

    def statparse(self, resp):
        """Internal: parse the response of a STAT, NEXT or LAST command."""
        if resp[:2] != '22':
            raise NNTPReplyError(resp)
        words = resp.split()
        nr = 0
        id = ''
        n = len(words)
        if n > 1:
            nr = words[1]
            if n > 2:
                id = words[2]
        return resp, nr, id

    def statcmd(self, line):
        """Internal: process a STAT, NEXT or LAST command."""
        resp = self.shortcmd(line)
        return self.statparse(resp)

    def stat(self, id):
        """Process a STAT command.  Argument:
        - id: article number or message id
        Returns:
        - resp: server response if successful
        - nr:   the article number
        - id:   the article id"""

        return self.statcmd('STAT ' + id)

    def next(self):
        """Process a NEXT command.  No arguments.  Return as for STAT."""
        return self.statcmd('NEXT')

    def last(self):
        """Process a LAST command.  No arguments.  Return as for STAT."""
        return self.statcmd('LAST')

    def artcmd(self, line, file=None):
        """Internal: process a HEAD, BODY or ARTICLE command."""
        resp, list = self.longcmd(line, file)
        resp, nr, id = self.statparse(resp)
        return resp, nr, id, list

    def head(self, id):
        """Process a HEAD command.  Argument:
        - id: article number or message id
        Returns:
        - resp: server response if successful
        - nr: article number
        - id: message id
        - list: the lines of the article's header"""

        return self.artcmd('HEAD ' + id)

    def body(self, id, file=None):
        """Process a BODY command.  Argument:
        - id: article number or message id
        - file: Filename string or file object to store the article in
        Returns:
        - resp: server response if successful
        - nr: article number
        - id: message id
        - list: the lines of the article's body or an empty list
                if file was used"""

        return self.artcmd('BODY ' + id, file)

    def article(self, id):
        """Process an ARTICLE command.  Argument:
        - id: article number or message id
        Returns:
        - resp: server response if successful
        - nr: article number
        - id: message id
        - list: the lines of the article"""

        return self.artcmd('ARTICLE ' + id)

    def slave(self):
        """Process a SLAVE command.  Returns:
        - resp: server response if successful"""

        return self.shortcmd('SLAVE')

    def xhdr(self, hdr, str):
        """Process an XHDR command (optional server extension).  Arguments:
        - hdr: the header type (e.g. 'subject')
        - str: an article nr, a message id, or a range nr1-nr2
        Returns:
        - resp: server response if successful
        - list: list of (nr, value) strings"""

        pat = re.compile('^([0-9]+) ?(.*)\n?')
        resp, lines = self.longcmd('XHDR ' + hdr + ' ' + str)
        for i in range(len(lines)):
            line = lines[i]
            m = pat.match(line)
            if m:
                lines[i] = m.group(1, 2)
        return resp, lines

    def xover(self,start,end):
        """Process an XOVER command (optional server extension) Arguments:
        - start: start of range
        - end: end of range
        Returns:
        - resp: server response if successful
        - list: list of (art-nr, subject, poster, date,
                         id, references, size, lines)"""

        resp, lines = self.longcmd('XOVER ' + start + '-' + end)
        xover_lines = []
        for line in lines:
            elem = line.split("\t")
            try:
                xover_lines.append((elem[0],
                                    elem[1],
                                    elem[2],
                                    elem[3],
                                    elem[4],
                                    elem[5].split(),
                                    elem[6],
                                    elem[7]))
            except IndexError:
                raise NNTPDataError(line)
        return resp,xover_lines

    def xgtitle(self, group):
        """Process an XGTITLE command (optional server extension) Arguments:
        - group: group name wildcard (i.e. news.*)
        Returns:
        - resp: server response if successful
        - list: list of (name,title) strings"""

        line_pat = re.compile("^([^ \t]+)[ \t]+(.*)$")
        resp, raw_lines = self.longcmd('XGTITLE ' + group)
        lines = []
        for raw_line in raw_lines:
            match = line_pat.search(raw_line.strip())
            if match:
                lines.append(match.group(1, 2))
        return resp, lines

    def xpath(self,id):
        """Process an XPATH command (optional server extension) Arguments:
        - id: Message id of article
        Returns:
        resp: server response if successful
        path: directory path to article"""

        resp = self.shortcmd("XPATH " + id)
        if resp[:3] != '223':
            raise NNTPReplyError(resp)
        try:
            [resp_num, path] = resp.split()
        except ValueError:
            raise NNTPReplyError(resp)
        else:
            return resp, path

    def date (self):
        """Process the DATE command. Arguments:
        None
        Returns:
        resp: server response if successful
        date: Date suitable for newnews/newgroups commands etc.
        time: Time suitable for newnews/newgroups commands etc."""

        resp = self.shortcmd("DATE")
        if resp[:3] != '111':
            raise NNTPReplyError(resp)
        elem = resp.split()
        if len(elem) != 2:
            raise NNTPDataError(resp)
        date = elem[1][2:8]
        time = elem[1][-6:]
        if len(date) != 6 or len(time) != 6:
            raise NNTPDataError(resp)
        return resp, date, time


    def post(self, f):
        """Process a POST command.  Arguments:
        - f: file containing the article
        Returns:
        - resp: server response if successful"""

        resp = self.shortcmd('POST')
        # Raises error_??? if posting is not allowed
        if resp[0] != '3':
            raise NNTPReplyError(resp)
        while 1:
            line = f.readline()
            if not line:
                break
            if line[-1] == '\n':
                line = line[:-1]
            if line[:1] == '.':
                line = '.' + line
            self.putline(line)
        self.putline('.')
        return self.getresp()

    def ihave(self, id, f):
        """Process an IHAVE command.  Arguments:
        - id: message-id of the article
        - f:  file containing the article
        Returns:
        - resp: server response if successful
        Note that if the server refuses the article an exception is raised."""

        resp = self.shortcmd('IHAVE ' + id)
        # Raises error_??? if the server already has it
        if resp[0] != '3':
            raise NNTPReplyError(resp)
        while 1:
            line = f.readline()
            if not line:
                break
            if line[-1] == '\n':
                line = line[:-1]
            if line[:1] == '.':
                line = '.' + line
            self.putline(line)
        self.putline('.')
        return self.getresp()

    def quit(self):
        """Process a QUIT command and close the socket.  Returns:
        - resp: server response if successful"""

        resp = self.shortcmd('QUIT')
        self.file.close()
        self.sock.close()
        del self.file, self.sock
        return resp


# Test retrieval when run as a script.
# Assumption: if there's a local news server, it's called 'news'.
# Assumption: if user queries a remote news server, it's named
# in the environment variable NNTPSERVER (used by slrn and kin)
# and we want readermode off.
if __name__ == '__main__':
    import os
    newshost = 'news' and os.environ["NNTPSERVER"]
    if newshost.find('.') == -1:
        mode = 'readermode'
    else:
        mode = None
    s = NNTP(newshost, readermode=mode)
    resp, count, first, last, name = s.group('comp.lang.python')
    print resp
    print 'Group', name, 'has', count, 'articles, range', first, 'to', last
    resp, subs = s.xhdr('subject', first + '-' + last)
    print resp
    for item in subs:
        print "%7s %s" % item
    resp = s.quit()
    print resp