cpython/Lib/nntplib.py

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# An NNTP client class. Based on RFC 977: Network News Transfer
# Protocol, by Brian Kantor and Phil Lapsley.
# Example:
#
# >>> from nntplib import NNTP
# >>> s = NNTP('charon')
# >>> resp, count, first, last, name = s.group('nlnet.misc')
# >>> print 'Group', name, 'has', count, 'articles, range', first, 'to', last
# Group nlnet.misc has 525 articles, range 6960 to 7485
# >>> 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.
# Imports
import regex
import socket
import string
# Exception raised when an error or invalid response is received
error_reply = 'nntplib.error_reply' # unexpected [123]xx reply
error_temp = 'nntplib.error_temp' # 4xx errors
error_perm = 'nntplib.error_perm' # 5xx errors
error_proto = 'nntplib.error_proto' # response does not begin with [1-5]
# 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', '230', '231']
# Line terminators (we always output CRLF, but accept any of CRLF, CR, LF)
CRLF = '\r\n'
# The class itself
class NNTP:
# Initialize an instance. Arguments:
# - host: hostname to connect to
# - port: port to connect to (default the standard NNTP port)
def __init__(self, host, port = NNTP_PORT):
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('r')
self.debugging = 0
self.welcome = self.getresp()
# 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):
if self.debugging: print '*welcome*', `self.welcome`
return self.welcome
# 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
def debug(self, level):
self.debugging = level
# Internal: send one line to the server, appending CRLF
def putline(self, line):
line = line + CRLF
if self.debugging > 1: print '*put*', `line`
self.sock.send(line)
# Internal: send one command to the server (through putline())
def putcmd(self, line):
if self.debugging: print '*cmd*', `line`
self.putline(line)
# Internal: return one line from the server, stripping CRLF.
# Raise EOFError if the connection is closed
def getline(self):
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
# Internal: get a response from the server.
# Raise various errors if the response indicates an error
def getresp(self):
resp = self.getline()
if self.debugging: print '*resp*', `resp`
c = resp[:1]
if c == '4':
raise error_temp, resp
if c == '5':
raise error_perm, resp
if c not in '123':
raise error_proto, resp
return resp
# Internal: get a response plus following text from the server.
# Raise various errors if the response indicates an error
def getlongresp(self):
resp = self.getresp()
if resp[:3] not in LONGRESP:
raise error_reply, resp
list = []
while 1:
line = self.getline()
if line == '.':
break
list.append(line)
return resp, list
# Internal: send a command and get the response
def shortcmd(self, line):
self.putcmd(line)
return self.getresp()
# Internal: send a command and get the response plus following text
def longcmd(self, line):
self.putcmd(line)
return self.getlongresp()
# Process a NEWGROUPS command. Arguments:
# - date: string 'yymmdd' indicating the date
# - time: string 'hhmmss' indicating the time
# Return:
# - resp: server response if succesful
# - list: list of newsgroup names
def newgroups(self, date, time):
return self.longcmd('NEWGROUPS ' + 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 succesful
# - list: list of article ids
def newnews(self, group, date, time):
cmd = 'NEWNEWS ' + group + ' ' + date + ' ' + time
return self.longcmd(cmd)
# Process a LIST command. Return:
# - resp: server response if succesful
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# - list: list of (group, last, first, flag) (strings)
def list(self):
resp, list = self.longcmd('LIST')
for i in range(len(list)):
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# Parse lines into "group last first flag"
list[i] = string.split(list[i])
return resp, list
# Process a GROUP command. Argument:
# - group: the group name
# Returns:
# - resp: server response if succesful
# - count: number of articles (string)
# - first: first article number (string)
# - last: last article number (string)
# - name: the group name
def group(self, name):
resp = self.shortcmd('GROUP ' + name)
if resp[:3] <> '211':
raise error_reply, resp
words = string.split(resp)
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 = string.lower(words[4])
return resp, count, first, last, name
# Process a HELP command. Returns:
# - resp: server response if succesful
# - list: list of strings
def help(self):
return self.longcmd('HELP')
# Internal: parse the response of a STAT, NEXT or LAST command
def statparse(self, resp):
if resp[:2] <> '22':
raise error_reply, resp
words = string.split(resp)
nr = 0
id = ''
n = len(words)
if n > 1:
nr = words[1]
if n > 2:
id = string.lower(words[2])
return resp, nr, id
# Internal: process a STAT, NEXT or LAST command
def statcmd(self, line):
resp = self.shortcmd(line)
return self.statparse(resp)
# Process a STAT command. Argument:
# - id: article number or message id
# Returns:
# - resp: server response if succesful
# - nr: the article number
# - id: the article id
def stat(self, id):
return self.statcmd('STAT ' + id)
# Process a NEXT command. No arguments. Return as for STAT
def next(self):
return self.statcmd('NEXT')
# Process a LAST command. No arguments. Return as for STAT
def last(self):
return self.statcmd('LAST')
# Internal: process a HEAD, BODY or ARTICLE command
def artcmd(self, line):
resp, list = self.longcmd(line)
resp, nr, id = self.statparse(resp)
return resp, nr, id, list
# Process a HEAD command. Argument:
# - id: article number or message id
# Returns:
# - resp: server response if succesful
# - list: the lines of the article's header
def head(self, id):
return self.artcmd('HEAD ' + id)
# Process a BODY command. Argument:
# - id: article number or message id
# Returns:
# - resp: server response if succesful
# - list: the lines of the article's body
def body(self, id):
return self.artcmd('BODY ' + id)
# Process an ARTICLE command. Argument:
# - id: article number or message id
# Returns:
# - resp: server response if succesful
# - list: the lines of the article
def article(self, id):
return self.artcmd('ARTICLE ' + id)
# Process a SLAVE command. Returns:
# - resp: server response if succesful
def slave(self):
return self.shortcmd('SLAVE')
# 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 succesful
# - list: list of (nr, value) strings
def xhdr(self, hdr, str):
resp, lines = self.longcmd('XHDR ' + hdr + ' ' + str)
for i in range(len(lines)):
line = lines[i]
n = regex.match('^[0-9]+', line)
nr = line[:n]
if n < len(line) and line[n] == ' ': n = n+1
lines[i] = (nr, line[n:])
return resp, lines
# Process a POST command. Arguments:
# - f: file containing the article
# Returns:
# - resp: server response if succesful
def post(self, f):
resp = self.shortcmd('POST')
# Raises error_??? if posting is not allowed
if resp[0] <> '3':
raise error_reply, resp
while 1:
line = f.readline()
if not line:
break
if line[-1] == '\n':
line = line[:-1]
if line == '.':
line = '..'
self.putline(line)
self.putline('.')
return self.getresp()
# Process an IHAVE command. Arguments:
# - id: message-id of the article
# - f: file containing the article
# Returns:
# - resp: server response if succesful
# Note that if the server refuses the article an exception is raised
def ihave(self, id, f):
resp = self.shortcmd('IHAVE ' + id)
# Raises error_??? if the server already has it
if resp[0] <> '3':
raise error_reply, resp
while 1:
line = f.readline()
if not line:
break
if line[-1] == '\n':
line = line[:-1]
if line == '.':
line = '..'
self.putline(line)
self.putline('.')
return self.getresp()
# Process a QUIT command and close the socket. Returns:
# - resp: server response if succesful
def quit(self):
resp = self.shortcmd('QUIT')
self.file.close()
self.sock.close()
del self.file, self.sock
return resp