"""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')
You can 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)
This class can work with any input object that supports a readline
method. If the input object has seek and tell capability, the
rewindbody method will work; also illegal lines will be pushed back
onto the input stream. If the input object lacks seek but has an
`unread' method that can push back a line of input, Message will use
that to push back illegal lines. Thus this class can be used to parse
messages coming from a buffered stream.
The optional `seekable' argument is provided as a workaround for
certain stdio libraries in which tell() discards buffered data before
discovering that the lseek() system call doesn't work. For maximum
portability, you should set the seekable argument to zero to prevent
that initial \code{tell} when passing in an unseekable object such as
a a file object created from a socket object. If it is 1 on entry --
which it is by default -- the tell() method of the open file object is
called once; if this raises an exception, seekable is reset to 0. For
other nonzero values of seekable, this test is not made.
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.
"""
# Cleanup and extensions by Eric S. Raymond <esr@thyrsus.com>
import time
__all__ = ["Message","AddressList","parsedate","parsedate_tz","mktime_tz"]
_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."""
if seekable == 1:
# Exercise tell() to make sure it works
# (and then assume seek() works, too)
try:
fp.tell()
except:
seekable = 0
else:
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
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
startofline = unread = tell = None
if hasattr(self.fp, 'unread'):
unread = self.fp.unread
elif self.seekable:
tell = self.fp.tell
while 1:
if tell:
try:
startofline = tell()
except IOError:
startofline = tell = None
self.seekable = 0
line = self.fp.readline()
if not line:
self.status = 'EOF in headers'
break
# Skip unix From name time lines
if firstline and line.startswith('From '):
self.unixfrom = self.unixfrom + line
continue
firstline = 0
if headerseen and line[0] in ' \t':
# It's a continuation line.
list.append(line)
x = (self.dict[headerseen] + "\n " + line.strip())
self.dict[headerseen] = x.strip()
continue
elif self.iscomment(line):
# It's a comment. Ignore it.
continue
elif self.islast(line):
# Note! No pushback here! The delimiter line gets eaten.
break
headerseen = self.isheader(line)
if headerseen:
# It's a legal header line, save it.
list.append(line)
self.dict[headerseen] = line[len(headerseen)+1:].strip()
continue
else:
# It's not a header line; throw it back and stop here.
if not self.dict:
self.status = 'No headers'
else:
self.status = 'Non-header line where header expected'
# Try to undo the read.
if unread:
unread(line)
elif tell:
self.fp.seek(startofline)
else:
self.status = self.status + '; bad seek'
break
def isheader(self, line):
"""Determine whether a given line is a legal header.
This method should return the header name, suitably canonicalized.
You may override this method in order to use Message parsing
on tagged data in RFC822-like formats with special header formats.
"""
i = line.find(':')
if i > 0:
return line[:i].lower()
else:
return None
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 recognize 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 iscomment(self, line):
"""Determine whether a line should be skipped entirely.
You may override this method in order to use Message parsing
on tagged data in RFC822-like formats that support embedded
comments or free-text data.
"""
return None
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 = name.lower() + ':'
n = len(name)
list = []
hit = 0
for line in self.headers:
if line[:n].lower() == name:
hit = 1
elif not line[:1].isspace():
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 = name.lower() + ':'
n = len(name)
list = []
hit = 0
for line in self.headers:
if hit:
if not line[:1].isspace():
break
elif line[:n].lower() == 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 ''.join(list)
def getheader(self, name, default=None):
"""Get the header value for a name.
This is the normal interface: it returns 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[name.lower()]
except KeyError:
return default
get = getheader
def getheaders(self, name):
"""Get all values for a header.
This returns a list of values for headers given more than once;
each value in the result list is stripped in the same way as the
result of getheader(). If the header is not given, return an
empty list.
"""
result = []
current = ''
have_header = 0
for s in self.getallmatchingheaders(name):
if s[0].isspace():
if current:
current = "%s\n %s" % (current, s.strip())
else:
current = s.strip()
else:
if have_header:
result.append(current)
current = s[s.find(":") + 1:].strip()
have_header = 1
if have_header:
result.append(current)
return result
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(). Scans all named headers, so it works
properly with multiple To: or Cc: headers for example.
"""
raw = []
for h in self.getallmatchingheaders(name):
if h[0] in ' \t':
raw.append(h)
else:
if raw:
raw.append(', ')
i = h.find(':')
if i > 0:
addr = h[i+1:]
raw.append(addr)
alladdrs = ''.join(raw)
a = AddrlistClass(alladdrs)
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[name.lower()]
def __setitem__(self, name, value):
"""Set the value of a header.
Note: This is not a perfect inversion of __getitem__, because
any changed headers get stuck at the end of the raw-headers list
rather than where the altered header was.
"""
del self[name] # Won't fail if it doesn't exist
self.dict[name.lower()] = value
text = name + ": " + value
lines = text.split("\n")
for line in lines:
self.headers.append(line + "\n")
def __delitem__(self, name):
"""Delete all occurrences of a specific header, if it is present."""
name = name.lower()
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 line[:n].lower() == name:
hit = 1
elif not line[:1].isspace():
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(name.lower())
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()
def __str__(self):
str = ''
for hdr in self.headers:
str = str + hdr
return str
# 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 str.replace('\\', '\\\\').replace('"', '\\"')
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.
Note: this class interface is deprecated and may be removed in the future.
Use rfc822.AddressList instead.
"""
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\n'
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 = [(' '.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 = [(' '.join(self.commentlist), addrspec)]
elif self.field[self.pos] == ':':
# address is a group
returnlist = []
fieldlen = len(self.field)
self.pos = self.pos + 1
while self.pos < len(self.field):
self.gotonext()
if self.pos < fieldlen and 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 = [(' '.join(plist) + ' (' + \
' '.join(self.commentlist) + ')', routeaddr)]
else: returnlist = [(' '.join(plist), routeaddr)]
else:
if plist:
returnlist = [(' '.join(self.commentlist), plist[0])]
elif self.field[self.pos] in self.specials:
self.pos = self.pos + 1
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 = ""
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('"%s"' % 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 ''.join(aslist)
aslist.append('@')
self.pos = self.pos + 1
self.gotonext()
return ''.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 ''.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 ''.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 '[%s]' % 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 ''.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. Phrases are canonicalized
by squeezing all runs of continuous whitespace into one space.
"""
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
class AddressList(AddrlistClass):
"""An AddressList encapsulates a list of parsed RFC822 addresses."""
def __init__(self, field):
AddrlistClass.__init__(self, field)
if field:
self.addresslist = self.getaddrlist()
else:
self.addresslist = []
def __len__(self):
return len(self.addresslist)
def __str__(self):
return ", ".join(map(dump_address_pair, self.addresslist))
def __add__(self, other):
# Set union
newaddr = AddressList(None)
newaddr.addresslist = self.addresslist[:]
for x in other.addresslist:
if not x in self.addresslist:
newaddr.addresslist.append(x)
return newaddr
def __iadd__(self, other):
# Set union, in-place
for x in other.addresslist:
if not x in self.addresslist:
self.addresslist.append(x)
return self
def __sub__(self, other):
# Set difference
newaddr = AddressList(None)
for x in self.addresslist:
if not x in other.addresslist:
newaddr.addresslist.append(x)
return newaddr
def __isub__(self, other):
# Set difference, in-place
for x in other.addresslist:
if x in self.addresslist:
self.addresslist.remove(x)
return self
def __getitem__(self, index):
# Make indexing, slices, and 'in' work
return self.addresslist[index]
def dump_address_pair(pair):
"""Dump a (name, address) pair in a canonicalized form."""
if pair[0]:
return '"' + pair[0] + '" <' + pair[1] + '>'
else:
return pair[1]
# Parse a date field
_monthnames = ['jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul',
'aug', 'sep', 'oct', 'nov', 'dec',
'january', 'february', 'march', 'april', 'may', 'june', 'july',
'august', 'september', 'october', 'november', 'december']
_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 (used in Canada)
'EST': -500, 'EDT': -400, # Eastern
'CST': -600, 'CDT': -500, # Central
'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 = data.split()
if data[0][-1] in (',', '.') or data[0].lower() in _daynames:
# There's a dayname here. Skip it
del data[0]
if len(data) == 3: # RFC 850 date, deprecated
stuff = data[0].split('-')
if len(stuff) == 3:
data = stuff + data[1:]
if len(data) == 4:
s = data[3]
i = s.find('+')
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
mm = mm.lower()
if not mm in _monthnames:
dd, mm = mm, dd.lower()
if not mm in _monthnames:
return None
mm = _monthnames.index(mm)+1
if mm > 12: mm = mm - 12
if dd[-1] == ',':
dd = dd[:-1]
i = yy.find(':')
if i > 0:
yy, tm = tm, yy
if yy[-1] == ',':
yy = yy[:-1]
if not yy[0].isdigit():
yy, tz = tz, yy
if tm[-1] == ',':
tm = tm[:-1]
tm = tm.split(':')
if len(tm) == 2:
[thh, tmm] = tm
tss = '0'
elif len(tm) == 3:
[thh, tmm, tss] = tm
else:
return None
try:
yy = int(yy)
dd = int(dd)
thh = int(thh)
tmm = int(tmm)
tss = int(tss)
except ValueError:
return None
tzoffset = None
tz = tz.upper()
if _timezones.has_key(tz):
tzoffset = _timezones[tz]
else:
try:
tzoffset = int(tz)
except ValueError:
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."""
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
def formatdate(timeval=None):
"""Returns time format preferred for Internet standards.
Sun, 06 Nov 1994 08:49:37 GMT ; RFC 822, updated by RFC 1123
"""
if timeval is None:
timeval = time.time()
return "%s" % time.strftime('%a, %d %b %Y %H:%M:%S GMT',
time.gmtime(timeval))
# 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')
tz = date[-1]
date = time.localtime(mktime_tz(date))
if date:
print 'ParsedDate:', time.asctime(date),
hhmmss = tz
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()
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