Lib/rfc822.py - platform/external/python/cpython3 - Gitiles

 # RFC-822 message manipulation class.
 #
 # XXX This is only a very rough sketch of a full RFC-822 parser;
 # in particular the tokenizing of addresses does not adhere to all the
 # quoting rules.
 #
 # Directions for use:
 #
 # To create a Message object: first open a file, e.g.:
 #   fp = open(file, 'r')
 # (or use any other legal way of getting an open file object, e.g. use
 # sys.stdin or call os.popen()).
 # Then pass the open file object to the Message() constructor:
 #   m = Message(fp)
 #
 # To get the text of a particular header there are several methods:
 #   str = m.getheader(name)
 #   str = m.getrawheader(name)
 # where name is the name of the header, e.g. 'Subject'.
 # The difference is that getheader() strips the leading and trailing
 # whitespace, while getrawheader() doesn't.  Both functions retain
 # embedded whitespace (including newlines) exactly as they are
 # specified in the header, and leave the case of the text unchanged.
 #
 # For addresses and address lists there are functions
 #   realname, mailaddress = m.getaddr(name) and
 #   list = m.getaddrlist(name)
 # where the latter returns a list of (realname, mailaddr) tuples.
 #
 # There is also a method
 #   time = m.getdate(name)
 # which parses a Date-like field and returns a time-compatible tuple,
 # i.e. a tuple such as returned by time.localtime() or accepted by
 # time.mktime().
 #
 # See the class definition for lower level access methods.
 #
 # There are also some utility functions here.


 import regex
 import string
 import time


 _blanklines = ('\r\n', '\n')		# Optimization for islast()


 class Message:

 	# Initialize the class instance and read the headers.

 	def __init__(self, fp, seekable = 1):
 		self.fp = fp
 		self.seekable = seekable
 		self.startofheaders = None
 		self.startofbody = None
 		#
 		if self.seekable:
 			try:
 				self.startofheaders = self.fp.tell()
 			except IOError:
 				self.seekable = 0
 		#
 		self.readheaders()
 		#
 		if self.seekable:
 			try:
 				self.startofbody = self.fp.tell()
 			except IOError:
 				self.seekable = 0


 	# Rewind the file to the start of the body (if seekable).

 	def rewindbody(self):
 		if not self.seekable:
 			raise IOError, "unseekable file"
 		self.fp.seek(self.startofbody)


 	# Read header lines up to the entirely blank line that
 	# terminates them.  The (normally blank) line that ends the
 	# headers is skipped, but not included in the returned list.
 	# If a non-header line ends the headers, (which is an error),
 	# an attempt is made to backspace over it; it is never
 	# included in the returned list.
 	#
 	# The variable self.status is set to the empty string if all
 	# went well, otherwise it is an error message.
 	# The variable self.headers is a completely uninterpreted list
 	# of lines contained in the header (so printing them will
 	# reproduce the header exactly as it appears in the file).

 	def readheaders(self):
 		self.unixfrom = ''
 		self.headers = list = []
 		self.status = ''
 		headerseen = 0
 		firstline = 1
 		while 1:
 			line = self.fp.readline()
 			if not line:
 				self.status = 'EOF in headers'
 				break
 			# Skip unix From name time lines
 			if firstline and line[:5] == 'From ':
 				self.unixfrom = self.unixfrom + line
 			        continue
 			firstline = 0
 			if self.islast(line):
 				break
 			elif headerseen and line[0] in ' \t':
 				# It's a continuation line.
 				list.append(line)
 			elif regex.match('^[!-9;-~]+:', line) >= 0:
 				# It's a header line.
 				list.append(line)
 				headerseen = 1
 			else:
 				# It's not a header line; stop here.
 				if not headerseen:
 					self.status = 'No headers'
 				else:
 					self.status = 'Bad header'
 				# Try to undo the read.
 				if self.seekable:
 					self.fp.seek(-len(line), 1)
 				else:
 					self.status = \
 						self.status + '; bad seek'
 				break


 	# Method to determine whether a line is a legal end of
 	# RFC-822 headers.  You may override this method if your
 	# application wants to bend the rules, e.g. to strip trailing
 	# whitespace, or to recognise MH template separators
 	# ('--------').  For convenience (e.g. for code reading from
 	# sockets) a line consisting of \r\n also matches.

 	def islast(self, line):
 		return line in _blanklines


 	# Look through the list of headers and find all lines matching
 	# a given header name (and their continuation lines).
 	# A list of the lines is returned, without interpretation.
 	# If the header does not occur, an empty list is returned.
 	# If the header occurs multiple times, all occurrences are
 	# returned.  Case is not important in the header name.

 	def getallmatchingheaders(self, name):
 		name = string.lower(name) + ':'
 		n = len(name)
 		list = []
 		hit = 0
 		for line in self.headers:
 			if string.lower(line[:n]) == name:
 				hit = 1
 			elif line[:1] not in string.whitespace:
 				hit = 0
 			if hit:
 				list.append(line)
 		return list


 	# Similar, but return only the first matching header (and its
 	# continuation lines).

 	def getfirstmatchingheader(self, name):
 		name = string.lower(name) + ':'
 		n = len(name)
 		list = []
 		hit = 0
 		for line in self.headers:
 			if hit:
 				if line[:1] not in string.whitespace:
 					break
 			elif string.lower(line[:n]) == name:
 				hit = 1
 			if hit:
 				list.append(line)
 		return list


 	# A higher-level interface to getfirstmatchingheader().
 	# Return a string containing the literal text of the header
 	# but with the keyword stripped.  All leading, trailing and
 	# embedded whitespace is kept in the string, however.
 	# Return None if the header does not occur.

 	def getrawheader(self, name):
 		list = self.getfirstmatchingheader(name)
 		if not list:
 			return None
 		list[0] = list[0][len(name) + 1:]
 		return string.joinfields(list, '')


 	# Going one step further: also strip leading and trailing
 	# whitespace.

 	def getheader(self, name):
 		text = self.getrawheader(name)
 		if text == None:
 			return None
 		return string.strip(text)


 	# Retrieve a single address from a header as a tuple, e.g.
 	# ('Guido van Rossum', 'guido@cwi.nl').

 	def getaddr(self, name):
 		data = self.getheader(name)
 		if not data:
 			return None, None
 		return parseaddr(data)

 	# Retrieve a list of addresses from a header, where each
 	# address is a tuple as returned by getaddr().

 	def getaddrlist(self, name):
 		# XXX This function is not really correct.  The split
 		# on ',' might fail in the case of commas within
 		# quoted strings.
 		data = self.getheader(name)
 		if not data:
 			return []
 		data = string.splitfields(data, ',')
 		for i in range(len(data)):
 			data[i] = parseaddr(data[i])
 		return data

 	# Retrieve a date field from a header as a tuple compatible
 	# with time.mktime().

 	def getdate(self, name):
 		data = self.getheader(name)
 		if not data:
 			return None
 		return parsedate(data)


 	# Access as a dictionary (only finds first header of each type):

 	def __len__(self):
 		types = {}
 		for line in self.headers:
 			if line[0] in string.whitespace: continue
 			i = string.find(line, ':')
 			if i > 0:
 				name = string.lower(line[:i])
 				types[name] = None
 		return len(types)

 	def __getitem__(self, name):
 		value = self.getheader(name)
 		if value is None: raise KeyError, name
 		return value

 	def has_key(self, name):
 		value = self.getheader(name)
 		return value is not None

 	def keys(self):
 		types = {}
 		for line in self.headers:
 			if line[0] in string.whitespace: continue
 			i = string.find(line, ':')
 			if i > 0:
 				name = line[:i]
 				key = string.lower(name)
 				types[key] = name
 		return types.values()

 	def values(self):
 		values = []
 		for name in self.keys():
 			values.append(self[name])
 		return values

 	def items(self):
 		items = []
 		for name in self.keys():
 			items.append(name, self[name])
 		return items


 # Utility functions
 # -----------------

 # XXX Should fix these to be really conformant.
 # XXX The inverses of the parse functions may also be useful.


 # Remove quotes from a string.

 def unquote(str):
 	if len(str) > 1:
 		if str[0] == '"' and str[-1:] == '"':
 			return str[1:-1]
 		if str[0] == '<' and str[-1:] == '>':
 			return str[1:-1]
 	return str


 # Parse an address into (name, address) tuple

 def parseaddr(address):
 	# This is probably not perfect
 	address = string.strip(address)
 	# Case 1: part of the address is in <xx@xx> form.
 	pos = regex.search('<.*>', address)
 	if pos >= 0:
 		name = address[:pos]
 		address = address[pos:]
 		length = regex.match('<.*>', address)
 		name = name + address[length:]
 		address = address[:length]
 	else:
 		# Case 2: part of the address is in (comment) form
 		pos = regex.search('(.*)', address)
 		if pos >= 0:
 			name = address[pos:]
 			address = address[:pos]
 			length = regex.match('(.*)', name)
 			address = address + name[length:]
 			name = name[:length]
 		else:
 			# Case 3: neither. Only an address
 			name = ''
 	name = string.strip(name)
 	address = string.strip(address)
 	if address and address[0] == '<' and address[-1] == '>':
 		address = address[1:-1]
 	if name and name[0] == '(' and name[-1] == ')':
 		name = name[1:-1]
 	return name, address


 # Parse a date field

 _monthnames = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul',
 	  'Aug', 'Sep', 'Oct', 'Nov', 'Dec']

 def parsedate(data):
 	# XXX This still mostly ignores timezone matters at the moment...
 	data = string.split(data)
 	if data[0][-1] == ',':
 		# There's a dayname here. Skip it
 		del data[0]
 	if len(data) == 4:
 		s = data[3]
 		i = string.find(s, '+')
 		if i > 0:
 			data[3:] = [s[:i], s[i+1:]]
 		else:
 			data.append('') # Dummy tz
 	if len(data) < 5:
 		return None
 	data = data[:5]
 	[dd, mm, yy, tm, tz] = data
 	if not mm in _monthnames:
 		return None
 	mm = _monthnames.index(mm)+1
 	tm = string.splitfields(tm, ':')
 	if len(tm) == 2:
 		[thh, tmm] = tm
 		tss = '0'
 	else:
 		[thh, tmm, tss] = tm
 	try:
 		yy = string.atoi(yy)
 		dd = string.atoi(dd)
 		thh = string.atoi(thh)
 		tmm = string.atoi(tmm)
 		tss = string.atoi(tss)
 	except string.atoi_error:
 		return None
 	tuple = (yy, mm, dd, thh, tmm, tss, 0, 0, 0)
 	return tuple


 # When used as script, run a small test program.
 # The first command line argument must be a filename containing one
 # message in RFC-822 format.

 if __name__ == '__main__':
 	import sys
 	file = '/ufs/guido/Mail/drafts/,1'
 	if sys.argv[1:]: file = sys.argv[1]
 	f = open(file, 'r')
 	m = Message(f)
 	print 'From:', m.getaddr('from')
 	print 'To:', m.getaddrlist('to')
 	print 'Subject:', m.getheader('subject')
 	print 'Date:', m.getheader('date')
 	date = m.getdate('date')
 	if date:
 		print 'ParsedDate:', time.asctime(date)
 	else:
 		print 'ParsedDate:', None
 	m.rewindbody()
 	n = 0
 	while f.readline():
 		n = n + 1
 	print 'Lines:', n
 	print '-'*70
 	print 'len =', len(m)
 	if m.has_key('Date'): print 'Date =', m['Date']
 	if m.has_key('X-Nonsense'): pass
 	print 'keys =', m.keys()
 	print 'values =', m.values()
 	print 'items =', m.items()
	# RFC-822 message manipulation class.
	#
	# XXX This is only a very rough sketch of a full RFC-822 parser;
	# in particular the tokenizing of addresses does not adhere to all the
	# quoting rules.
	#
	# Directions for use:
	#
	# To create a Message object: first open a file, e.g.:
	# fp = open(file, 'r')
	# (or use any other legal way of getting an open file object, e.g. use
	# sys.stdin or call os.popen()).
	# Then pass the open file object to the Message() constructor:
	# m = Message(fp)
	#
	# To get the text of a particular header there are several methods:
	# str = m.getheader(name)
	# str = m.getrawheader(name)
	# where name is the name of the header, e.g. 'Subject'.
	# The difference is that getheader() strips the leading and trailing
	# whitespace, while getrawheader() doesn't. Both functions retain
	# embedded whitespace (including newlines) exactly as they are
	# specified in the header, and leave the case of the text unchanged.
	#
	# For addresses and address lists there are functions
	# realname, mailaddress = m.getaddr(name) and
	# list = m.getaddrlist(name)
	# where the latter returns a list of (realname, mailaddr) tuples.
	#
	# There is also a method
	# time = m.getdate(name)
	# which parses a Date-like field and returns a time-compatible tuple,
	# i.e. a tuple such as returned by time.localtime() or accepted by
	# time.mktime().
	#
	# See the class definition for lower level access methods.
	#
	# There are also some utility functions here.


	import regex
	import string
	import time


	_blanklines = ('\r\n', '\n') # Optimization for islast()


	class Message:

	# Initialize the class instance and read the headers.

	def __init__(self, fp, seekable = 1):
	self.fp = fp
	self.seekable = seekable
	self.startofheaders = None
	self.startofbody = None
	#
	if self.seekable:
	try:
	self.startofheaders = self.fp.tell()
	except IOError:
	self.seekable = 0
	#
	self.readheaders()
	#
	if self.seekable:
	try:
	self.startofbody = self.fp.tell()
	except IOError:
	self.seekable = 0


	# Rewind the file to the start of the body (if seekable).

	def rewindbody(self):
	if not self.seekable:
	raise IOError, "unseekable file"
	self.fp.seek(self.startofbody)


	# Read header lines up to the entirely blank line that
	# terminates them. The (normally blank) line that ends the
	# headers is skipped, but not included in the returned list.
	# If a non-header line ends the headers, (which is an error),
	# an attempt is made to backspace over it; it is never
	# included in the returned list.
	#
	# The variable self.status is set to the empty string if all
	# went well, otherwise it is an error message.
	# The variable self.headers is a completely uninterpreted list
	# of lines contained in the header (so printing them will
	# reproduce the header exactly as it appears in the file).

	def readheaders(self):
	self.unixfrom = ''
	self.headers = list = []
	self.status = ''
	headerseen = 0
	firstline = 1
	while 1:
	line = self.fp.readline()
	if not line:
	self.status = 'EOF in headers'
	break
	# Skip unix From name time lines
	if firstline and line[:5] == 'From ':
	self.unixfrom = self.unixfrom + line
	continue
	firstline = 0
	if self.islast(line):
	break
	elif headerseen and line[0] in ' \t':
	# It's a continuation line.
	list.append(line)
	elif regex.match('^[!-9;-~]+:', line) >= 0:
	# It's a header line.
	list.append(line)
	headerseen = 1
	else:
	# It's not a header line; stop here.
	if not headerseen:
	self.status = 'No headers'
	else:
	self.status = 'Bad header'
	# Try to undo the read.
	if self.seekable:
	self.fp.seek(-len(line), 1)
	else:
	self.status = \
	self.status + '; bad seek'
	break


	# Method to determine whether a line is a legal end of
	# RFC-822 headers. You may override this method if your
	# application wants to bend the rules, e.g. to strip trailing
	# whitespace, or to recognise MH template separators
	# ('--------'). For convenience (e.g. for code reading from
	# sockets) a line consisting of \r\n also matches.

	def islast(self, line):
	return line in _blanklines


	# Look through the list of headers and find all lines matching
	# a given header name (and their continuation lines).
	# A list of the lines is returned, without interpretation.
	# If the header does not occur, an empty list is returned.
	# If the header occurs multiple times, all occurrences are
	# returned. Case is not important in the header name.

	def getallmatchingheaders(self, name):
	name = string.lower(name) + ':'
	n = len(name)
	list = []
	hit = 0
	for line in self.headers:
	if string.lower(line[:n]) == name:
	hit = 1
	elif line[:1] not in string.whitespace:
	hit = 0
	if hit:
	list.append(line)
	return list


	# Similar, but return only the first matching header (and its
	# continuation lines).

	def getfirstmatchingheader(self, name):
	name = string.lower(name) + ':'
	n = len(name)
	list = []
	hit = 0
	for line in self.headers:
	if hit:
	if line[:1] not in string.whitespace:
	break
	elif string.lower(line[:n]) == name:
	hit = 1
	if hit:
	list.append(line)
	return list


	# A higher-level interface to getfirstmatchingheader().
	# Return a string containing the literal text of the header
	# but with the keyword stripped. All leading, trailing and
	# embedded whitespace is kept in the string, however.
	# Return None if the header does not occur.

	def getrawheader(self, name):
	list = self.getfirstmatchingheader(name)
	if not list:
	return None
	list[0] = list[0][len(name) + 1:]
	return string.joinfields(list, '')


	# Going one step further: also strip leading and trailing
	# whitespace.

	def getheader(self, name):
	text = self.getrawheader(name)
	if text == None:
	return None
	return string.strip(text)


	# Retrieve a single address from a header as a tuple, e.g.
	# ('Guido van Rossum', 'guido@cwi.nl').

	def getaddr(self, name):
	data = self.getheader(name)
	if not data:
	return None, None
	return parseaddr(data)

	# Retrieve a list of addresses from a header, where each
	# address is a tuple as returned by getaddr().

	def getaddrlist(self, name):
	# XXX This function is not really correct. The split
	# on ',' might fail in the case of commas within
	# quoted strings.
	data = self.getheader(name)
	if not data:
	return []
	data = string.splitfields(data, ',')
	for i in range(len(data)):
	data[i] = parseaddr(data[i])
	return data

	# Retrieve a date field from a header as a tuple compatible
	# with time.mktime().

	def getdate(self, name):
	data = self.getheader(name)
	if not data:
	return None
	return parsedate(data)


	# Access as a dictionary (only finds first header of each type):

	def __len__(self):
	types = {}
	for line in self.headers:
	if line[0] in string.whitespace: continue
	i = string.find(line, ':')
	if i > 0:
	name = string.lower(line[:i])
	types[name] = None
	return len(types)

	def __getitem__(self, name):
	value = self.getheader(name)
	if value is None: raise KeyError, name
	return value

	def has_key(self, name):
	value = self.getheader(name)
	return value is not None

	def keys(self):
	types = {}
	for line in self.headers:
	if line[0] in string.whitespace: continue
	i = string.find(line, ':')
	if i > 0:
	name = line[:i]
	key = string.lower(name)
	types[key] = name
	return types.values()

	def values(self):
	values = []
	for name in self.keys():
	values.append(self[name])
	return values

	def items(self):
	items = []
	for name in self.keys():
	items.append(name, self[name])
	return items



	# Utility functions
	# -----------------

	# XXX Should fix these to be really conformant.
	# XXX The inverses of the parse functions may also be useful.


	# Remove quotes from a string.

	def unquote(str):
	if len(str) > 1:
	if str[0] == '"' and str[-1:] == '"':
	return str[1:-1]
	if str[0] == '<' and str[-1:] == '>':
	return str[1:-1]
	return str


	# Parse an address into (name, address) tuple

	def parseaddr(address):
	# This is probably not perfect
	address = string.strip(address)
	# Case 1: part of the address is in <xx@xx> form.
	pos = regex.search('<.*>', address)
	if pos >= 0:
	name = address[:pos]
	address = address[pos:]
	length = regex.match('<.*>', address)
	name = name + address[length:]
	address = address[:length]
	else:
	# Case 2: part of the address is in (comment) form
	pos = regex.search('(.*)', address)
	if pos >= 0:
	name = address[pos:]
	address = address[:pos]
	length = regex.match('(.*)', name)
	address = address + name[length:]
	name = name[:length]
	else:
	# Case 3: neither. Only an address
	name = ''
	name = string.strip(name)
	address = string.strip(address)
	if address and address[0] == '<' and address[-1] == '>':
	address = address[1:-1]
	if name and name[0] == '(' and name[-1] == ')':
	name = name[1:-1]
	return name, address


	# Parse a date field

	_monthnames = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul',
	'Aug', 'Sep', 'Oct', 'Nov', 'Dec']

	def parsedate(data):
	# XXX This still mostly ignores timezone matters at the moment...
	data = string.split(data)
	if data[0][-1] == ',':
	# There's a dayname here. Skip it
	del data[0]
	if len(data) == 4:
	s = data[3]
	i = string.find(s, '+')
	if i > 0:
	data[3:] = [s[:i], s[i+1:]]
	else:
	data.append('') # Dummy tz
	if len(data) < 5:
	return None
	data = data[:5]
	[dd, mm, yy, tm, tz] = data
	if not mm in _monthnames:
	return None
	mm = _monthnames.index(mm)+1
	tm = string.splitfields(tm, ':')
	if len(tm) == 2:
	[thh, tmm] = tm
	tss = '0'
	else:
	[thh, tmm, tss] = tm
	try:
	yy = string.atoi(yy)
	dd = string.atoi(dd)
	thh = string.atoi(thh)
	tmm = string.atoi(tmm)
	tss = string.atoi(tss)
	except string.atoi_error:
	return None
	tuple = (yy, mm, dd, thh, tmm, tss, 0, 0, 0)
	return tuple


	# When used as script, run a small test program.
	# The first command line argument must be a filename containing one
	# message in RFC-822 format.

	if __name__ == '__main__':
	import sys
	file = '/ufs/guido/Mail/drafts/,1'
	if sys.argv[1:]: file = sys.argv[1]
	f = open(file, 'r')
	m = Message(f)
	print 'From:', m.getaddr('from')
	print 'To:', m.getaddrlist('to')
	print 'Subject:', m.getheader('subject')
	print 'Date:', m.getheader('date')
	date = m.getdate('date')
	if date:
	print 'ParsedDate:', time.asctime(date)
	else:
	print 'ParsedDate:', None
	m.rewindbody()
	n = 0
	while f.readline():
	n = n + 1
	print 'Lines:', n
	print '-'*70
	print 'len =', len(m)
	if m.has_key('Date'): print 'Date =', m['Date']
	if m.has_key('X-Nonsense'): pass
	print 'keys =', m.keys()
	print 'values =', m.values()
	print 'items =', m.items()