| """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",] |
| |
| # maximal line length when calling readline(). This is to prevent |
| # reading arbitrary length lines. RFC 3977 limits NNTP line length to |
| # 512 characters, including CRLF. We have selected 2048 just to be on |
| # the safe side. |
| _MAXLINE = 2048 |
| |
| |
| # Exceptions raised when an error or invalid response is received |
| class NNTPError(Exception): |
| """Base class for all nntplib exceptions""" |
| def __init__(self, *args): |
| 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, usenetrc=True): |
| """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 commands, such as `group'. If you get |
| unexpected NNTPPermanentErrors, you might need to set |
| readermode. |
| """ |
| self.host = host |
| self.port = port |
| self.sock = socket.create_connection((host, 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 usenetrc and 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*', repr(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*', repr(line) |
| self.sock.sendall(line) |
| |
| def putcmd(self, line): |
| """Internal: send one command to the server (through putline()).""" |
| if self.debugging: print '*cmd*', repr(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(_MAXLINE + 1) |
| if len(line) > _MAXLINE: |
| raise NNTPDataError('line too long') |
| if self.debugging > 1: |
| print '*get*', repr(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*', repr(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, file=None): |
| """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, file) |
| |
| def newnews(self, group, date, time, file=None): |
| """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 message ids""" |
| |
| cmd = 'NEWNEWS ' + group + ' ' + date + ' ' + time |
| return self.longcmd(cmd, file) |
| |
| def list(self, file=None): |
| """Process a LIST command. Return: |
| - resp: server response if successful |
| - list: list of (group, last, first, flag) (strings)""" |
| |
| resp, list = self.longcmd('LIST', file) |
| for i in range(len(list)): |
| # Parse lines into "group last first flag" |
| list[i] = tuple(list[i].split()) |
| return resp, list |
| |
| def description(self, group): |
| |
| """Get a description for a single group. If more than one |
| group matches ('group' is a pattern), return the first. If no |
| group matches, return an empty string. |
| |
| This elides the response code from the server, since it can |
| only be '215' or '285' (for xgtitle) anyway. If the response |
| code is needed, use the 'descriptions' method. |
| |
| NOTE: This neither checks for a wildcard in 'group' nor does |
| it check whether the group actually exists.""" |
| |
| resp, lines = self.descriptions(group) |
| if len(lines) == 0: |
| return "" |
| else: |
| return lines[0][1] |
| |
| def descriptions(self, group_pattern): |
| """Get descriptions for a range of groups.""" |
| line_pat = re.compile("^(?P<group>[^ \t]+)[ \t]+(.*)$") |
| # Try the more std (acc. to RFC2980) LIST NEWSGROUPS first |
| resp, raw_lines = self.longcmd('LIST NEWSGROUPS ' + group_pattern) |
| if resp[:3] != "215": |
| # Now the deprecated XGTITLE. This either raises an error |
| # or succeeds with the same output structure as LIST |
| # NEWSGROUPS. |
| resp, raw_lines = self.longcmd('XGTITLE ' + group_pattern) |
| 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 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, file=None): |
| """Process a HELP command. Returns: |
| - resp: server response if successful |
| - list: list of strings""" |
| |
| return self.longcmd('HELP',file) |
| |
| 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 message 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, file=None): |
| """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, file) |
| 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, file=None): |
| """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, file) |
| 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, file=None): |
| """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, file) |
| 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 |
