home *** CD-ROM | disk | FTP | other *** search
- """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 string
- import time
-
-
- _blanklines = ('\r\n', '\n') # Optimization for islast()
-
-
- class Message:
- """Represents a single RFC-822-compliant message."""
-
- def __init__(self, fp, seekable = 1):
- """Initialize the class instance and read the headers."""
- 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
-
- def rewindbody(self):
- """Rewind the file to the start of the body (if seekable)."""
- if not self.seekable:
- raise IOError, "unseekable file"
- self.fp.seek(self.startofbody)
-
- def readheaders(self):
- """Read header lines.
-
- 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).
- """
- self.dict = {}
- self.unixfrom = ''
- self.headers = list = []
- self.status = ''
- headerseen = ""
- 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)
- x = (self.dict[headerseen] + "\n " +
- string.strip(line))
- self.dict[headerseen] = string.strip(x)
- elif ':' in line:
- # It's a header line.
- list.append(line)
- i = string.find(line, ':')
- headerseen = string.lower(line[:i])
- self.dict[headerseen] = string.strip(
- line[i+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
-
- def islast(self, line):
- """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.
- """
- return line in _blanklines
-
- def getallmatchingheaders(self, name):
- """Find all header lines matching a given header name.
-
- 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.
- """
- 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
-
- def getfirstmatchingheader(self, name):
- """Get the first header line matching name.
-
- This is similar to getallmatchingheaders, but it returns
- only the first matching header (and its continuation
- lines).
- """
- 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
-
- def getrawheader(self, name):
- """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.
- """
-
- list = self.getfirstmatchingheader(name)
- if not list:
- return None
- list[0] = list[0][len(name) + 1:]
- return string.joinfields(list, '')
-
- def getheader(self, name):
- """Get the header value for a name.
-
- This is the normal interface: it return a stripped
- version of the header value for a given header name,
- or None if it doesn't exist. This uses the dictionary
- version which finds the *last* such header.
- """
- try:
- return self.dict[string.lower(name)]
- except KeyError:
- return None
-
- def getaddr(self, name):
- """Get a single address from a header, as a tuple.
-
- An example return value:
- ('Guido van Rossum', 'guido@cwi.nl')
- """
- # New, by Ben Escoto
- alist = self.getaddrlist(name)
- if alist:
- return alist[0]
- else:
- return (None, None)
-
- def getaddrlist(self, name):
- """Get a list of addresses from a header.
-
- Retrieves a list of addresses from a header, where each
- address is a tuple as returned by getaddr().
- """
- # New, by Ben Escoto
- try:
- data = self[name]
- except KeyError:
- return []
- a = AddrlistClass(data)
- return a.getaddrlist()
-
- def getdate(self, name):
- """Retrieve a date field from a header.
-
- Retrieves a date field from the named header, returning
- a tuple compatible with time.mktime().
- """
- try:
- data = self[name]
- except KeyError:
- return None
- return parsedate(data)
-
- def getdate_tz(self, name):
- """Retrieve a date field from a header as a 10-tuple.
-
- The first 9 elements make up a tuple compatible with
- time.mktime(), and the 10th is the offset of the poster's
- time zone from GMT/UTC.
- """
- try:
- data = self[name]
- except KeyError:
- return None
- return parsedate_tz(data)
-
-
- # Access as a dictionary (only finds *last* header of each type):
-
- def __len__(self):
- """Get the number of headers in a message."""
- return len(self.dict)
-
- def __getitem__(self, name):
- """Get a specific header, as from a dictionary."""
- return self.dict[string.lower(name)]
-
- def __delitem__(self, name):
- """Delete all occurrences of a specific header, if it is present."""
- name = string.lower(name)
- if not self.dict.has_key(name):
- return
- del self.dict[name]
- name = name + ':'
- n = len(name)
- list = []
- hit = 0
- for i in range(len(self.headers)):
- line = self.headers[i]
- if string.lower(line[:n]) == name:
- hit = 1
- elif line[:1] not in string.whitespace:
- hit = 0
- if hit:
- list.append(i)
- list.reverse()
- for i in list:
- del self.headers[i]
-
- def has_key(self, name):
- """Determine whether a message contains the named header."""
- return self.dict.has_key(string.lower(name))
-
- def keys(self):
- """Get all of a message's header field names."""
- return self.dict.keys()
-
- def values(self):
- """Get all of a message's header field values."""
- return self.dict.values()
-
- def items(self):
- """Get all of a message's headers.
-
- Returns a list of name, value tuples.
- """
- return self.dict.items()
-
-
-
- # Utility functions
- # -----------------
-
- # XXX Should fix unquote() and quote() to be really conformant.
- # XXX The inverses of the parse functions may also be useful.
-
-
- def unquote(str):
- """Remove quotes from a string."""
- 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
-
-
- def quote(str):
- """Add quotes around a string."""
- return '"%s"' % string.join(
- string.split(
- string.join(
- string.split(str, '\\'),
- '\\\\'),
- '"'),
- '\\"')
-
-
- def parseaddr(address):
- """Parse an address into a (realname, mailaddr) tuple."""
- a = AddrlistClass(address)
- list = a.getaddrlist()
- if not list:
- return (None, None)
- else:
- return list[0]
-
-
- class AddrlistClass:
- """Address parser class by Ben Escoto.
-
- To understand what this class does, it helps to have a copy of
- RFC-822 in front of you.
- """
-
- def __init__(self, field):
- """Initialize a new instance.
-
- `field' is an unparsed address header field, containing
- one or more addresses.
- """
- self.specials = '()<>@,:;.\"[]'
- self.pos = 0
- self.LWS = ' \t'
- self.CR = '\r'
- self.atomends = self.specials + self.LWS + self.CR
-
- self.field = field
- self.commentlist = []
-
- def gotonext(self):
- """Parse up to the start of the next address."""
- while self.pos < len(self.field):
- if self.field[self.pos] in self.LWS + '\n\r':
- self.pos = self.pos + 1
- elif self.field[self.pos] == '(':
- self.commentlist.append(self.getcomment())
- else: break
-
- def getaddrlist(self):
- """Parse all addresses.
-
- Returns a list containing all of the addresses.
- """
- ad = self.getaddress()
- if ad:
- return ad + self.getaddrlist()
- else: return []
-
- def getaddress(self):
- """Parse the next address."""
- self.commentlist = []
- self.gotonext()
-
- oldpos = self.pos
- oldcl = self.commentlist
- plist = self.getphraselist()
-
- self.gotonext()
- returnlist = []
-
- if self.pos >= len(self.field):
- # Bad email address technically, no domain.
- if plist:
- returnlist = [(string.join(self.commentlist), plist[0])]
-
- elif self.field[self.pos] in '.@':
- # email address is just an addrspec
- # this isn't very efficient since we start over
- self.pos = oldpos
- self.commentlist = oldcl
- addrspec = self.getaddrspec()
- returnlist = [(string.join(self.commentlist), addrspec)]
-
- elif self.field[self.pos] == ':':
- # address is a group
- returnlist = []
-
- self.pos = self.pos + 1
- while self.pos < len(self.field):
- self.gotonext()
- if self.field[self.pos] == ';':
- self.pos = self.pos + 1
- break
- returnlist = returnlist + self.getaddress()
-
- elif self.field[self.pos] == '<':
- # Address is a phrase then a route addr
- routeaddr = self.getrouteaddr()
-
- if self.commentlist:
- returnlist = [(string.join(plist) + ' (' + \
- string.join(self.commentlist) + ')', routeaddr)]
- else: returnlist = [(string.join(plist), routeaddr)]
-
- else:
- if plist:
- returnlist = [(string.join(self.commentlist), plist[0])]
-
- self.gotonext()
- if self.pos < len(self.field) and self.field[self.pos] == ',':
- self.pos = self.pos + 1
- return returnlist
-
- def getrouteaddr(self):
- """Parse a route address (Return-path value).
-
- This method just skips all the route stuff and returns the addrspec.
- """
- if self.field[self.pos] != '<':
- return
-
- expectroute = 0
- self.pos = self.pos + 1
- self.gotonext()
- adlist = None
- while self.pos < len(self.field):
- if expectroute:
- self.getdomain()
- expectroute = 0
- elif self.field[self.pos] == '>':
- self.pos = self.pos + 1
- break
- elif self.field[self.pos] == '@':
- self.pos = self.pos + 1
- expectroute = 1
- elif self.field[self.pos] == ':':
- self.pos = self.pos + 1
- expectaddrspec = 1
- else:
- adlist = self.getaddrspec()
- self.pos = self.pos + 1
- break
- self.gotonext()
-
- return adlist
-
- def getaddrspec(self):
- """Parse an RFC-822 addr-spec."""
- aslist = []
-
- self.gotonext()
- while self.pos < len(self.field):
- if self.field[self.pos] == '.':
- aslist.append('.')
- self.pos = self.pos + 1
- elif self.field[self.pos] == '"':
- aslist.append(self.getquote())
- elif self.field[self.pos] in self.atomends:
- break
- else: aslist.append(self.getatom())
- self.gotonext()
-
- if self.pos >= len(self.field) or self.field[self.pos] != '@':
- return string.join(aslist, '')
-
- aslist.append('@')
- self.pos = self.pos + 1
- self.gotonext()
- return string.join(aslist, '') + self.getdomain()
-
- def getdomain(self):
- """Get the complete domain name from an address."""
- sdlist = []
- while self.pos < len(self.field):
- if self.field[self.pos] in self.LWS:
- self.pos = self.pos + 1
- elif self.field[self.pos] == '(':
- self.commentlist.append(self.getcomment())
- elif self.field[self.pos] == '[':
- sdlist.append(self.getdomainliteral())
- elif self.field[self.pos] == '.':
- self.pos = self.pos + 1
- sdlist.append('.')
- elif self.field[self.pos] in self.atomends:
- break
- else: sdlist.append(self.getatom())
-
- return string.join(sdlist, '')
-
- def getdelimited(self, beginchar, endchars, allowcomments = 1):
- """Parse a header fragment delimited by special characters.
-
- `beginchar' is the start character for the fragment.
- If self is not looking at an instance of `beginchar' then
- getdelimited returns the empty string.
-
- `endchars' is a sequence of allowable end-delimiting characters.
- Parsing stops when one of these is encountered.
-
- If `allowcomments' is non-zero, embedded RFC-822 comments
- are allowed within the parsed fragment.
- """
- if self.field[self.pos] != beginchar:
- return ''
-
- slist = ['']
- quote = 0
- self.pos = self.pos + 1
- while self.pos < len(self.field):
- if quote == 1:
- slist.append(self.field[self.pos])
- quote = 0
- elif self.field[self.pos] in endchars:
- self.pos = self.pos + 1
- break
- elif allowcomments and self.field[self.pos] == '(':
- slist.append(self.getcomment())
- elif self.field[self.pos] == '\\':
- quote = 1
- else:
- slist.append(self.field[self.pos])
- self.pos = self.pos + 1
-
- return string.join(slist, '')
-
- def getquote(self):
- """Get a quote-delimited fragment from self's field."""
- return self.getdelimited('"', '"\r', 0)
-
- def getcomment(self):
- """Get a parenthesis-delimited fragment from self's field."""
- return self.getdelimited('(', ')\r', 1)
-
- def getdomainliteral(self):
- """Parse an RFC-822 domain-literal."""
- return self.getdelimited('[', ']\r', 0)
-
- def getatom(self):
- """Parse an RFC-822 atom."""
- atomlist = ['']
-
- while self.pos < len(self.field):
- if self.field[self.pos] in self.atomends:
- break
- else: atomlist.append(self.field[self.pos])
- self.pos = self.pos + 1
-
- return string.join(atomlist, '')
-
- def getphraselist(self):
- """Parse a sequence of RFC-822 phrases.
-
- A phrase is a sequence of words, which are in turn either
- RFC-822 atoms or quoted-strings.
- """
- plist = []
-
- while self.pos < len(self.field):
- if self.field[self.pos] in self.LWS:
- self.pos = self.pos + 1
- elif self.field[self.pos] == '"':
- plist.append(self.getquote())
- elif self.field[self.pos] == '(':
- self.commentlist.append(self.getcomment())
- elif self.field[self.pos] in self.atomends:
- break
- else: plist.append(self.getatom())
-
- return plist
-
-
- # Parse a date field
-
- _monthnames = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul',
- 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
- _daynames = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']
-
- # The timezone table does not include the military time zones defined
- # in RFC822, other than Z. According to RFC1123, the description in
- # RFC822 gets the signs wrong, so we can't rely on any such time
- # zones. RFC1123 recommends that numeric timezone indicators be used
- # instead of timezone names.
-
- _timezones = {'UT':0, 'UTC':0, 'GMT':0, 'Z':0,
- 'AST': -400, 'ADT': -300, # Atlantic standard
- 'EST': -500, 'EDT': -400, # Eastern
- 'CST': -600, 'CDT':-500, # Centreal
- 'MST':-700, 'MDT':-600, # Mountain
- 'PST':-800, 'PDT':-700 # Pacific
- }
-
-
- def parsedate_tz(data):
- """Convert a date string to a time tuple.
-
- Accounts for military timezones.
- """
- data = string.split(data)
- if data[0][-1] == ',' or data[0] in _daynames:
- # There's a dayname here. Skip it
- del data[0]
- if len(data) == 3: # RFC 850 date, deprecated
- stuff = string.split(data[0], '-')
- if len(stuff) == 3:
- data = stuff + data[1:]
- 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:
- dd, mm, yy, tm, tz = mm, dd, tm, yy, tz
- 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
- tzoffset=None
- tz=string.upper(tz)
- if _timezones.has_key(tz):
- tzoffset=_timezones[tz]
- else:
- try:
- tzoffset=string.atoi(tz)
- except string.atoi_error:
- pass
- # Convert a timezone offset into seconds ; -0500 -> -18000
- if tzoffset:
- if tzoffset < 0:
- tzsign = -1
- tzoffset = -tzoffset
- else:
- tzsign = 1
- tzoffset = tzsign * ( (tzoffset/100)*3600 + (tzoffset % 100)*60)
- tuple = (yy, mm, dd, thh, tmm, tss, 0, 0, 0, tzoffset)
- return tuple
-
-
- def parsedate(data):
- """Convert a time string to a time tuple."""
- t=parsedate_tz(data)
- if type(t)==type( () ):
- return t[:9]
- else: return t
-
-
- def mktime_tz(data):
- """Turn a 10-tuple as returned by parsedate_tz() into a UTC timestamp.
-
- Minor glitch: this first interprets the first 8 elements as a
- local time and then compensates for the timezone difference;
- this may yield a slight error around daylight savings time
- switch dates. Not enough to worry about for common use.
-
- """
- if data[9] is None:
- # No zone info, so localtime is better assumption than GMT
- return time.mktime(data[:8] + (-1,))
- else:
- t = time.mktime(data[:8] + (0,))
- return t - data[9] - time.timezone
-
-
- # 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, os
- file = os.path.join(os.environ['HOME'], 'Mail/inbox/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_tz('date')
- if date:
- print 'ParsedDate:', time.asctime(date[:-1]),
- hhmmss = date[-1]
- hhmm, ss = divmod(hhmmss, 60)
- hh, mm = divmod(hhmm, 60)
- print "%+03d%02d" % (hh, mm),
- if ss: print ".%02d" % ss,
- print
- 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()
-