source file: /System/Library/Frameworks/Python.framework/Versions/2.3/lib/python2.3/rfc822.py
file stats: 579 lines, 70 executed: 12.1% covered
   1. """RFC 2822 message manipulation.
   2. 
   3. Note: This is only a very rough sketch of a full RFC-822 parser; in particular
   4. the tokenizing of addresses does not adhere to all the quoting rules.
   5. 
   6. Note: RFC 2822 is a long awaited update to RFC 822.  This module should
   7. conform to RFC 2822, and is thus mis-named (it's not worth renaming it).  Some
   8. effort at RFC 2822 updates have been made, but a thorough audit has not been
   9. performed.  Consider any RFC 2822 non-conformance to be a bug.
  10. 
  11.     RFC 2822: http://www.faqs.org/rfcs/rfc2822.html
  12.     RFC 822 : http://www.faqs.org/rfcs/rfc822.html (obsolete)
  13. 
  14. Directions for use:
  15. 
  16. To create a Message object: first open a file, e.g.:
  17. 
  18.   fp = open(file, 'r')
  19. 
  20. You can use any other legal way of getting an open file object, e.g. use
  21. sys.stdin or call os.popen().  Then pass the open file object to the Message()
  22. constructor:
  23. 
  24.   m = Message(fp)
  25. 
  26. This class can work with any input object that supports a readline method.  If
  27. the input object has seek and tell capability, the rewindbody method will
  28. work; also illegal lines will be pushed back onto the input stream.  If the
  29. input object lacks seek but has an `unread' method that can push back a line
  30. of input, Message will use that to push back illegal lines.  Thus this class
  31. can be used to parse messages coming from a buffered stream.
  32. 
  33. The optional `seekable' argument is provided as a workaround for certain stdio
  34. libraries in which tell() discards buffered data before discovering that the
  35. lseek() system call doesn't work.  For maximum portability, you should set the
  36. seekable argument to zero to prevent that initial \code{tell} when passing in
  37. an unseekable object such as a a file object created from a socket object.  If
  38. it is 1 on entry -- which it is by default -- the tell() method of the open
  39. file object is called once; if this raises an exception, seekable is reset to
  40. 0.  For other nonzero values of seekable, this test is not made.
  41. 
  42. To get the text of a particular header there are several methods:
  43. 
  44.   str = m.getheader(name)
  45.   str = m.getrawheader(name)
  46. 
  47. where name is the name of the header, e.g. 'Subject'.  The difference is that
  48. getheader() strips the leading and trailing whitespace, while getrawheader()
  49. doesn't.  Both functions retain embedded whitespace (including newlines)
  50. exactly as they are specified in the header, and leave the case of the text
  51. unchanged.
  52. 
  53. For addresses and address lists there are functions
  54. 
  55.   realname, mailaddress = m.getaddr(name)
  56.   list = m.getaddrlist(name)
  57. 
  58. where the latter returns a list of (realname, mailaddr) tuples.
  59. 
  60. There is also a method
  61. 
  62.   time = m.getdate(name)
  63. 
  64. which parses a Date-like field and returns a time-compatible tuple,
  65. i.e. a tuple such as returned by time.localtime() or accepted by
  66. time.mktime().
  67. 
  68. See the class definition for lower level access methods.
  69. 
  70. There are also some utility functions here.
  71. """
  72. # Cleanup and extensions by Eric S. Raymond <esr@thyrsus.com>
  73. 
  74. import time
  75. 
  76. __all__ = ["Message","AddressList","parsedate","parsedate_tz","mktime_tz"]
  77. 
  78. _blanklines = ('\r\n', '\n')            # Optimization for islast()
  79. 
  80. 
  81. class Message:
  82.     """Represents a single RFC 2822-compliant message."""
  83. 
  84.     def __init__(self, fp, seekable = 1):
  85.         """Initialize the class instance and read the headers."""
  86.         if seekable == 1:
  87.             # Exercise tell() to make sure it works
  88.             # (and then assume seek() works, too)
  89.             try:
  90.                 fp.tell()
  91.             except (AttributeError, IOError):
  92.                 seekable = 0
  93.             else:
  94.                 seekable = 1
  95.         self.fp = fp
  96.         self.seekable = seekable
  97.         self.startofheaders = None
  98.         self.startofbody = None
  99.         #
 100.         if self.seekable:
 101.             try:
 102.                 self.startofheaders = self.fp.tell()
 103.             except IOError:
 104.                 self.seekable = 0
 105.         #
 106.         self.readheaders()
 107.         #
 108.         if self.seekable:
 109.             try:
 110.                 self.startofbody = self.fp.tell()
 111.             except IOError:
 112.                 self.seekable = 0
 113. 
 114.     def rewindbody(self):
 115.         """Rewind the file to the start of the body (if seekable)."""
 116.         if not self.seekable:
 117.             raise IOError, "unseekable file"
 118.         self.fp.seek(self.startofbody)
 119. 
 120.     def readheaders(self):
 121.         """Read header lines.
 122. 
 123.         Read header lines up to the entirely blank line that terminates them.
 124.         The (normally blank) line that ends the headers is skipped, but not
 125.         included in the returned list.  If a non-header line ends the headers,
 126.         (which is an error), an attempt is made to backspace over it; it is
 127.         never included in the returned list.
 128. 
 129.         The variable self.status is set to the empty string if all went well,
 130.         otherwise it is an error message.  The variable self.headers is a
 131.         completely uninterpreted list of lines contained in the header (so
 132.         printing them will reproduce the header exactly as it appears in the
 133.         file).
 134.         """
 135.         self.dict = {}
 136.         self.unixfrom = ''
 137.         self.headers = list = []
 138.         self.status = ''
 139.         headerseen = ""
 140.         firstline = 1
 141.         startofline = unread = tell = None
 142.         if hasattr(self.fp, 'unread'):
 143.             unread = self.fp.unread
 144.         elif self.seekable:
 145.             tell = self.fp.tell
 146.         while 1:
 147.             if tell:
 148.                 try:
 149.                     startofline = tell()
 150.                 except IOError:
 151.                     startofline = tell = None
 152.                     self.seekable = 0
 153.             line = self.fp.readline()
 154.             if not line:
 155.                 self.status = 'EOF in headers'
 156.                 break
 157.             # Skip unix From name time lines
 158.             if firstline and line.startswith('From '):
 159.                 self.unixfrom = self.unixfrom + line
 160.                 continue
 161.             firstline = 0
 162.             if headerseen and line[0] in ' \t':
 163.                 # It's a continuation line.
 164.                 list.append(line)
 165.                 x = (self.dict[headerseen] + "\n " + line.strip())
 166.                 self.dict[headerseen] = x.strip()
 167.                 continue
 168.             elif self.iscomment(line):
 169.                 # It's a comment.  Ignore it.
 170.                 continue
 171.             elif self.islast(line):
 172.                 # Note! No pushback here!  The delimiter line gets eaten.
 173.                 break
 174.             headerseen = self.isheader(line)
 175.             if headerseen:
 176.                 # It's a legal header line, save it.
 177.                 list.append(line)
 178.                 self.dict[headerseen] = line[len(headerseen)+1:].strip()
 179.                 continue
 180.             else:
 181.                 # It's not a header line; throw it back and stop here.
 182.                 if not self.dict:
 183.                     self.status = 'No headers'
 184.                 else:
 185.                     self.status = 'Non-header line where header expected'
 186.                 # Try to undo the read.
 187.                 if unread:
 188.                     unread(line)
 189.                 elif tell:
 190.                     self.fp.seek(startofline)
 191.                 else:
 192.                     self.status = self.status + '; bad seek'
 193.                 break
 194. 
 195.     def isheader(self, line):
 196.         """Determine whether a given line is a legal header.
 197. 
 198.         This method should return the header name, suitably canonicalized.
 199.         You may override this method in order to use Message parsing on tagged
 200.         data in RFC 2822-like formats with special header formats.
 201.         """
 202.         i = line.find(':')
 203.         if i > 0:
 204.             return line[:i].lower()
 205.         else:
 206.             return None
 207. 
 208.     def islast(self, line):
 209.         """Determine whether a line is a legal end of RFC 2822 headers.
 210. 
 211.         You may override this method if your application wants to bend the
 212.         rules, e.g. to strip trailing whitespace, or to recognize MH template
 213.         separators ('--------').  For convenience (e.g. for code reading from
 214.         sockets) a line consisting of \r\n also matches.
 215.         """
 216.         return line in _blanklines
 217. 
 218.     def iscomment(self, line):
 219.         """Determine whether a line should be skipped entirely.
 220. 
 221.         You may override this method in order to use Message parsing on tagged
 222.         data in RFC 2822-like formats that support embedded comments or
 223.         free-text data.
 224.         """
 225.         return False
 226. 
 227.     def getallmatchingheaders(self, name):
 228.         """Find all header lines matching a given header name.
 229. 
 230.         Look through the list of headers and find all lines matching a given
 231.         header name (and their continuation lines).  A list of the lines is
 232.         returned, without interpretation.  If the header does not occur, an
 233.         empty list is returned.  If the header occurs multiple times, all
 234.         occurrences are returned.  Case is not important in the header name.
 235.         """
 236.         name = name.lower() + ':'
 237.         n = len(name)
 238.         list = []
 239.         hit = 0
 240.         for line in self.headers:
 241.             if line[:n].lower() == name:
 242.                 hit = 1
 243.             elif not line[:1].isspace():
 244.                 hit = 0
 245.             if hit:
 246.                 list.append(line)
 247.         return list
 248. 
 249.     def getfirstmatchingheader(self, name):
 250.         """Get the first header line matching name.
 251. 
 252.         This is similar to getallmatchingheaders, but it returns only the
 253.         first matching header (and its continuation lines).
 254.         """
 255.         name = name.lower() + ':'
 256.         n = len(name)
 257.         list = []
 258.         hit = 0
 259.         for line in self.headers:
 260.             if hit:
 261.                 if not line[:1].isspace():
 262.                     break
 263.             elif line[:n].lower() == name:
 264.                 hit = 1
 265.             if hit:
 266.                 list.append(line)
 267.         return list
 268. 
 269.     def getrawheader(self, name):
 270.         """A higher-level interface to getfirstmatchingheader().
 271. 
 272.         Return a string containing the literal text of the header but with the
 273.         keyword stripped.  All leading, trailing and embedded whitespace is
 274.         kept in the string, however.  Return None if the header does not
 275.         occur.
 276.         """
 277. 
 278.         list = self.getfirstmatchingheader(name)
 279.         if not list:
 280.             return None
 281.         list[0] = list[0][len(name) + 1:]
 282.         return ''.join(list)
 283. 
 284.     def getheader(self, name, default=None):
 285.         """Get the header value for a name.
 286. 
 287.         This is the normal interface: it returns a stripped version of the
 288.         header value for a given header name, or None if it doesn't exist.
 289.         This uses the dictionary version which finds the *last* such header.
 290.         """
 291.         try:
 292.             return self.dict[name.lower()]
 293.         except KeyError:
 294.             return default
 295.     get = getheader
 296. 
 297.     def getheaders(self, name):
 298.         """Get all values for a header.
 299. 
 300.         This returns a list of values for headers given more than once; each
 301.         value in the result list is stripped in the same way as the result of
 302.         getheader().  If the header is not given, return an empty list.
 303.         """
 304.         result = []
 305.         current = ''
 306.         have_header = 0
 307.         for s in self.getallmatchingheaders(name):
 308.             if s[0].isspace():
 309.                 if current:
 310.                     current = "%s\n %s" % (current, s.strip())
 311.                 else:
 312.                     current = s.strip()
 313.             else:
 314.                 if have_header:
 315.                     result.append(current)
 316.                 current = s[s.find(":") + 1:].strip()
 317.                 have_header = 1
 318.         if have_header:
 319.             result.append(current)
 320.         return result
 321. 
 322.     def getaddr(self, name):
 323.         """Get a single address from a header, as a tuple.
 324. 
 325.         An example return value:
 326.         ('Guido van Rossum', 'guido@cwi.nl')
 327.         """
 328.         # New, by Ben Escoto
 329.         alist = self.getaddrlist(name)
 330.         if alist:
 331.             return alist[0]
 332.         else:
 333.             return (None, None)
 334. 
 335.     def getaddrlist(self, name):
 336.         """Get a list of addresses from a header.
 337. 
 338.         Retrieves a list of addresses from a header, where each address is a
 339.         tuple as returned by getaddr().  Scans all named headers, so it works
 340.         properly with multiple To: or Cc: headers for example.
 341.         """
 342.         raw = []
 343.         for h in self.getallmatchingheaders(name):
 344.             if h[0] in ' \t':
 345.                 raw.append(h)
 346.             else:
 347.                 if raw:
 348.                     raw.append(', ')
 349.                 i = h.find(':')
 350.                 if i > 0:
 351.                     addr = h[i+1:]
 352.                 raw.append(addr)
 353.         alladdrs = ''.join(raw)
 354.         a = AddressList(alladdrs)
 355.         return a.addresslist
 356. 
 357.     def getdate(self, name):
 358.         """Retrieve a date field from a header.
 359. 
 360.         Retrieves a date field from the named header, returning a tuple
 361.         compatible with time.mktime().
 362.         """
 363.         try:
 364.             data = self[name]
 365.         except KeyError:
 366.             return None
 367.         return parsedate(data)
 368. 
 369.     def getdate_tz(self, name):
 370.         """Retrieve a date field from a header as a 10-tuple.
 371. 
 372.         The first 9 elements make up a tuple compatible with time.mktime(),
 373.         and the 10th is the offset of the poster's time zone from GMT/UTC.
 374.         """
 375.         try:
 376.             data = self[name]
 377.         except KeyError:
 378.             return None
 379.         return parsedate_tz(data)
 380. 
 381. 
 382.     # Access as a dictionary (only finds *last* header of each type):
 383. 
 384.     def __len__(self):
 385.         """Get the number of headers in a message."""
 386.         return len(self.dict)
 387. 
 388.     def __getitem__(self, name):
 389.         """Get a specific header, as from a dictionary."""
 390.         return self.dict[name.lower()]
 391. 
 392.     def __setitem__(self, name, value):
 393.         """Set the value of a header.
 394. 
 395.         Note: This is not a perfect inversion of __getitem__, because any
 396.         changed headers get stuck at the end of the raw-headers list rather
 397.         than where the altered header was.
 398.         """
 399.         del self[name] # Won't fail if it doesn't exist
 400.         self.dict[name.lower()] = value
 401.         text = name + ": " + value
 402.         lines = text.split("\n")
 403.         for line in lines:
 404.             self.headers.append(line + "\n")
 405. 
 406.     def __delitem__(self, name):
 407.         """Delete all occurrences of a specific header, if it is present."""
 408.         name = name.lower()
 409.         if not name in self.dict:
 410.             return
 411.         del self.dict[name]
 412.         name = name + ':'
 413.         n = len(name)
 414.         list = []
 415.         hit = 0
 416.         for i in range(len(self.headers)):
 417.             line = self.headers[i]
 418.             if line[:n].lower() == name:
 419.                 hit = 1
 420.             elif not line[:1].isspace():
 421.                 hit = 0
 422.             if hit:
 423.                 list.append(i)
 424.         list.reverse()
 425.         for i in list:
 426.             del self.headers[i]
 427. 
 428.     def setdefault(self, name, default=""):
 429.         lowername = name.lower()
 430.         if lowername in self.dict:
 431.             return self.dict[lowername]
 432.         else:
 433.             text = name + ": " + default
 434.             lines = text.split("\n")
 435.             for line in lines:
 436.                 self.headers.append(line + "\n")
 437.             self.dict[lowername] = default
 438.             return default
 439. 
 440.     def has_key(self, name):
 441.         """Determine whether a message contains the named header."""
 442.         return name.lower() in self.dict
 443. 
 444.     def __contains__(self, name):
 445.         """Determine whether a message contains the named header."""
 446.         return name.lower() in self.dict
 447. 
 448.     def keys(self):
 449.         """Get all of a message's header field names."""
 450.         return self.dict.keys()
 451. 
 452.     def values(self):
 453.         """Get all of a message's header field values."""
 454.         return self.dict.values()
 455. 
 456.     def items(self):
 457.         """Get all of a message's headers.
 458. 
 459.         Returns a list of name, value tuples.
 460.         """
 461.         return self.dict.items()
 462. 
 463.     def __str__(self):
 464.         str = ''
 465.         for hdr in self.headers:
 466.             str = str + hdr
 467.         return str
 468. 
 469. 
 470. # Utility functions
 471. # -----------------
 472. 
 473. # XXX Should fix unquote() and quote() to be really conformant.
 474. # XXX The inverses of the parse functions may also be useful.
 475. 
 476. 
 477. def unquote(str):
 478.     """Remove quotes from a string."""
 479.     if len(str) > 1:
 480.         if str.startswith('"') and str.endswith('"'):
 481.             return str[1:-1].replace('\\\\', '\\').replace('\\"', '"')
 482.         if str.startswith('<') and str.endswith('>'):
 483.             return str[1:-1]
 484.     return str
 485. 
 486. 
 487. def quote(str):
 488.     """Add quotes around a string."""
 489.     return str.replace('\\', '\\\\').replace('"', '\\"')
 490. 
 491. 
 492. def parseaddr(address):
 493.     """Parse an address into a (realname, mailaddr) tuple."""
 494.     a = AddressList(address)
 495.     list = a.addresslist
 496.     if not list:
 497.         return (None, None)
 498.     else:
 499.         return list[0]
 500. 
 501. 
 502. class AddrlistClass:
 503.     """Address parser class by Ben Escoto.
 504. 
 505.     To understand what this class does, it helps to have a copy of
 506.     RFC 2822 in front of you.
 507. 
 508.     http://www.faqs.org/rfcs/rfc2822.html
 509. 
 510.     Note: this class interface is deprecated and may be removed in the future.
 511.     Use rfc822.AddressList instead.
 512.     """
 513. 
 514.     def __init__(self, field):
 515.         """Initialize a new instance.
 516. 
 517.         `field' is an unparsed address header field, containing one or more
 518.         addresses.
 519.         """
 520.         self.specials = '()<>@,:;.\"[]'
 521.         self.pos = 0
 522.         self.LWS = ' \t'
 523.         self.CR = '\r\n'
 524.         self.atomends = self.specials + self.LWS + self.CR
 525.         # Note that RFC 2822 now specifies `.' as obs-phrase, meaning that it
 526.         # is obsolete syntax.  RFC 2822 requires that we recognize obsolete
 527.         # syntax, so allow dots in phrases.
 528.         self.phraseends = self.atomends.replace('.', '')
 529.         self.field = field
 530.         self.commentlist = []
 531. 
 532.     def gotonext(self):
 533.         """Parse up to the start of the next address."""
 534.         while self.pos < len(self.field):
 535.             if self.field[self.pos] in self.LWS + '\n\r':
 536.                 self.pos = self.pos + 1
 537.             elif self.field[self.pos] == '(':
 538.                 self.commentlist.append(self.getcomment())
 539.             else: break
 540. 
 541.     def getaddrlist(self):
 542.         """Parse all addresses.
 543. 
 544.         Returns a list containing all of the addresses.
 545.         """
 546.         result = []
 547.         while 1:
 548.             ad = self.getaddress()
 549.             if ad:
 550.                 result += ad
 551.             else:
 552.                 break
 553.         return result
 554. 
 555.     def getaddress(self):
 556.         """Parse the next address."""
 557.         self.commentlist = []
 558.         self.gotonext()
 559. 
 560.         oldpos = self.pos
 561.         oldcl = self.commentlist
 562.         plist = self.getphraselist()
 563. 
 564.         self.gotonext()
 565.         returnlist = []
 566. 
 567.         if self.pos >= len(self.field):
 568.             # Bad email address technically, no domain.
 569.             if plist:
 570.                 returnlist = [(' '.join(self.commentlist), plist[0])]
 571. 
 572.         elif self.field[self.pos] in '.@':
 573.             # email address is just an addrspec
 574.             # this isn't very efficient since we start over
 575.             self.pos = oldpos
 576.             self.commentlist = oldcl
 577.             addrspec = self.getaddrspec()
 578.             returnlist = [(' '.join(self.commentlist), addrspec)]
 579. 
 580.         elif self.field[self.pos] == ':':
 581.             # address is a group
 582.             returnlist = []
 583. 
 584.             fieldlen = len(self.field)
 585.             self.pos = self.pos + 1
 586.             while self.pos < len(self.field):
 587.                 self.gotonext()
 588.                 if self.pos < fieldlen and self.field[self.pos] == ';':
 589.                     self.pos = self.pos + 1
 590.                     break
 591.                 returnlist = returnlist + self.getaddress()
 592. 
 593.         elif self.field[self.pos] == '<':
 594.             # Address is a phrase then a route addr
 595.             routeaddr = self.getrouteaddr()
 596. 
 597.             if self.commentlist:
 598.                 returnlist = [(' '.join(plist) + ' (' + \
 599.                          ' '.join(self.commentlist) + ')', routeaddr)]
 600.             else: returnlist = [(' '.join(plist), routeaddr)]
 601. 
 602.         else:
 603.             if plist:
 604.                 returnlist = [(' '.join(self.commentlist), plist[0])]
 605.             elif self.field[self.pos] in self.specials:
 606.                 self.pos = self.pos + 1
 607. 
 608.         self.gotonext()
 609.         if self.pos < len(self.field) and self.field[self.pos] == ',':
 610.             self.pos = self.pos + 1
 611.         return returnlist
 612. 
 613.     def getrouteaddr(self):
 614.         """Parse a route address (Return-path value).
 615. 
 616.         This method just skips all the route stuff and returns the addrspec.
 617.         """
 618.         if self.field[self.pos] != '<':
 619.             return
 620. 
 621.         expectroute = 0
 622.         self.pos = self.pos + 1
 623.         self.gotonext()
 624.         adlist = ""
 625.         while self.pos < len(self.field):
 626.             if expectroute:
 627.                 self.getdomain()
 628.                 expectroute = 0
 629.             elif self.field[self.pos] == '>':
 630.                 self.pos = self.pos + 1
 631.                 break
 632.             elif self.field[self.pos] == '@':
 633.                 self.pos = self.pos + 1
 634.                 expectroute = 1
 635.             elif self.field[self.pos] == ':':
 636.                 self.pos = self.pos + 1
 637.             else:
 638.                 adlist = self.getaddrspec()
 639.                 self.pos = self.pos + 1
 640.                 break
 641.             self.gotonext()
 642. 
 643.         return adlist
 644. 
 645.     def getaddrspec(self):
 646.         """Parse an RFC 2822 addr-spec."""
 647.         aslist = []
 648. 
 649.         self.gotonext()
 650.         while self.pos < len(self.field):
 651.             if self.field[self.pos] == '.':
 652.                 aslist.append('.')
 653.                 self.pos = self.pos + 1
 654.             elif self.field[self.pos] == '"':
 655.                 aslist.append('"%s"' % self.getquote())
 656.             elif self.field[self.pos] in self.atomends:
 657.                 break
 658.             else: aslist.append(self.getatom())
 659.             self.gotonext()
 660. 
 661.         if self.pos >= len(self.field) or self.field[self.pos] != '@':
 662.             return ''.join(aslist)
 663. 
 664.         aslist.append('@')
 665.         self.pos = self.pos + 1
 666.         self.gotonext()
 667.         return ''.join(aslist) + self.getdomain()
 668. 
 669.     def getdomain(self):
 670.         """Get the complete domain name from an address."""
 671.         sdlist = []
 672.         while self.pos < len(self.field):
 673.             if self.field[self.pos] in self.LWS:
 674.                 self.pos = self.pos + 1
 675.             elif self.field[self.pos] == '(':
 676.                 self.commentlist.append(self.getcomment())
 677.             elif self.field[self.pos] == '[':
 678.                 sdlist.append(self.getdomainliteral())
 679.             elif self.field[self.pos] == '.':
 680.                 self.pos = self.pos + 1
 681.                 sdlist.append('.')
 682.             elif self.field[self.pos] in self.atomends:
 683.                 break
 684.             else: sdlist.append(self.getatom())
 685.         return ''.join(sdlist)
 686. 
 687.     def getdelimited(self, beginchar, endchars, allowcomments = 1):
 688.         """Parse a header fragment delimited by special characters.
 689. 
 690.         `beginchar' is the start character for the fragment.  If self is not
 691.         looking at an instance of `beginchar' then getdelimited returns the
 692.         empty string.
 693. 
 694.         `endchars' is a sequence of allowable end-delimiting characters.
 695.         Parsing stops when one of these is encountered.
 696. 
 697.         If `allowcomments' is non-zero, embedded RFC 2822 comments are allowed
 698.         within the parsed fragment.
 699.         """
 700.         if self.field[self.pos] != beginchar:
 701.             return ''
 702. 
 703.         slist = ['']
 704.         quote = 0
 705.         self.pos = self.pos + 1
 706.         while self.pos < len(self.field):
 707.             if quote == 1:
 708.                 slist.append(self.field[self.pos])
 709.                 quote = 0
 710.             elif self.field[self.pos] in endchars:
 711.                 self.pos = self.pos + 1
 712.                 break
 713.             elif allowcomments and self.field[self.pos] == '(':
 714.                 slist.append(self.getcomment())
 715.             elif self.field[self.pos] == '\\':
 716.                 quote = 1
 717.             else:
 718.                 slist.append(self.field[self.pos])
 719.             self.pos = self.pos + 1
 720. 
 721.         return ''.join(slist)
 722. 
 723.     def getquote(self):
 724.         """Get a quote-delimited fragment from self's field."""
 725.         return self.getdelimited('"', '"\r', 0)
 726. 
 727.     def getcomment(self):
 728.         """Get a parenthesis-delimited fragment from self's field."""
 729.         return self.getdelimited('(', ')\r', 1)
 730. 
 731.     def getdomainliteral(self):
 732.         """Parse an RFC 2822 domain-literal."""
 733.         return '[%s]' % self.getdelimited('[', ']\r', 0)
 734. 
 735.     def getatom(self, atomends=None):
 736.         """Parse an RFC 2822 atom.
 737. 
 738.         Optional atomends specifies a different set of end token delimiters
 739.         (the default is to use self.atomends).  This is used e.g. in
 740.         getphraselist() since phrase endings must not include the `.' (which
 741.         is legal in phrases)."""
 742.         atomlist = ['']
 743.         if atomends is None:
 744.             atomends = self.atomends
 745. 
 746.         while self.pos < len(self.field):
 747.             if self.field[self.pos] in atomends:
 748.                 break
 749.             else: atomlist.append(self.field[self.pos])
 750.             self.pos = self.pos + 1
 751. 
 752.         return ''.join(atomlist)
 753. 
 754.     def getphraselist(self):
 755.         """Parse a sequence of RFC 2822 phrases.
 756. 
 757.         A phrase is a sequence of words, which are in turn either RFC 2822
 758.         atoms or quoted-strings.  Phrases are canonicalized by squeezing all
 759.         runs of continuous whitespace into one space.
 760.         """
 761.         plist = []
 762. 
 763.         while self.pos < len(self.field):
 764.             if self.field[self.pos] in self.LWS:
 765.                 self.pos = self.pos + 1
 766.             elif self.field[self.pos] == '"':
 767.                 plist.append(self.getquote())
 768.             elif self.field[self.pos] == '(':
 769.                 self.commentlist.append(self.getcomment())
 770.             elif self.field[self.pos] in self.phraseends:
 771.                 break
 772.             else:
 773.                 plist.append(self.getatom(self.phraseends))
 774. 
 775.         return plist
 776. 
 777. class AddressList(AddrlistClass):
 778.     """An AddressList encapsulates a list of parsed RFC 2822 addresses."""
 779.     def __init__(self, field):
 780.         AddrlistClass.__init__(self, field)
 781.         if field:
 782.             self.addresslist = self.getaddrlist()
 783.         else:
 784.             self.addresslist = []
 785. 
 786.     def __len__(self):
 787.         return len(self.addresslist)
 788. 
 789.     def __str__(self):
 790.         return ", ".join(map(dump_address_pair, self.addresslist))
 791. 
 792.     def __add__(self, other):
 793.         # Set union
 794.         newaddr = AddressList(None)
 795.         newaddr.addresslist = self.addresslist[:]
 796.         for x in other.addresslist:
 797.             if not x in self.addresslist:
 798.                 newaddr.addresslist.append(x)
 799.         return newaddr
 800. 
 801.     def __iadd__(self, other):
 802.         # Set union, in-place
 803.         for x in other.addresslist:
 804.             if not x in self.addresslist:
 805.                 self.addresslist.append(x)
 806.         return self
 807. 
 808.     def __sub__(self, other):
 809.         # Set difference
 810.         newaddr = AddressList(None)
 811.         for x in self.addresslist:
 812.             if not x in other.addresslist:
 813.                 newaddr.addresslist.append(x)
 814.         return newaddr
 815. 
 816.     def __isub__(self, other):
 817.         # Set difference, in-place
 818.         for x in other.addresslist:
 819.             if x in self.addresslist:
 820.                 self.addresslist.remove(x)
 821.         return self
 822. 
 823.     def __getitem__(self, index):
 824.         # Make indexing, slices, and 'in' work
 825.         return self.addresslist[index]
 826. 
 827. def dump_address_pair(pair):
 828.     """Dump a (name, address) pair in a canonicalized form."""
 829.     if pair[0]:
 830.         return '"' + pair[0] + '" <' + pair[1] + '>'
 831.     else:
 832.         return pair[1]
 833. 
 834. # Parse a date field
 835. 
 836. _monthnames = ['jan', 'feb', 'mar', 'apr', 'may', 'jun', 'jul',
 837.                'aug', 'sep', 'oct', 'nov', 'dec',
 838.                'january', 'february', 'march', 'april', 'may', 'june', 'july',
 839.                'august', 'september', 'october', 'november', 'december']
 840. _daynames = ['mon', 'tue', 'wed', 'thu', 'fri', 'sat', 'sun']
 841. 
 842. # The timezone table does not include the military time zones defined
 843. # in RFC822, other than Z.  According to RFC1123, the description in
 844. # RFC822 gets the signs wrong, so we can't rely on any such time
 845. # zones.  RFC1123 recommends that numeric timezone indicators be used
 846. # instead of timezone names.
 847. 
 848. _timezones = {'UT':0, 'UTC':0, 'GMT':0, 'Z':0,
 849.               'AST': -400, 'ADT': -300,  # Atlantic (used in Canada)
 850.               'EST': -500, 'EDT': -400,  # Eastern
 851.               'CST': -600, 'CDT': -500,  # Central
 852.               'MST': -700, 'MDT': -600,  # Mountain
 853.               'PST': -800, 'PDT': -700   # Pacific
 854.               }
 855. 
 856. 
 857. def parsedate_tz(data):
 858.     """Convert a date string to a time tuple.
 859. 
 860.     Accounts for military timezones.
 861.     """
 862.     if not data:
 863.         return None
 864.     data = data.split()
 865.     if data[0][-1] in (',', '.') or data[0].lower() in _daynames:
 866.         # There's a dayname here. Skip it
 867.         del data[0]
 868.     if len(data) == 3: # RFC 850 date, deprecated
 869.         stuff = data[0].split('-')
 870.         if len(stuff) == 3:
 871.             data = stuff + data[1:]
 872.     if len(data) == 4:
 873.         s = data[3]
 874.         i = s.find('+')
 875.         if i > 0:
 876.             data[3:] = [s[:i], s[i+1:]]
 877.         else:
 878.             data.append('') # Dummy tz
 879.     if len(data) < 5:
 880.         return None
 881.     data = data[:5]
 882.     [dd, mm, yy, tm, tz] = data
 883.     mm = mm.lower()
 884.     if not mm in _monthnames:
 885.         dd, mm = mm, dd.lower()
 886.         if not mm in _monthnames:
 887.             return None
 888.     mm = _monthnames.index(mm)+1
 889.     if mm > 12: mm = mm - 12
 890.     if dd[-1] == ',':
 891.         dd = dd[:-1]
 892.     i = yy.find(':')
 893.     if i > 0:
 894.         yy, tm = tm, yy
 895.     if yy[-1] == ',':
 896.         yy = yy[:-1]
 897.     if not yy[0].isdigit():
 898.         yy, tz = tz, yy
 899.     if tm[-1] == ',':
 900.         tm = tm[:-1]
 901.     tm = tm.split(':')
 902.     if len(tm) == 2:
 903.         [thh, tmm] = tm
 904.         tss = '0'
 905.     elif len(tm) == 3:
 906.         [thh, tmm, tss] = tm
 907.     else:
 908.         return None
 909.     try:
 910.         yy = int(yy)
 911.         dd = int(dd)
 912.         thh = int(thh)
 913.         tmm = int(tmm)
 914.         tss = int(tss)
 915.     except ValueError:
 916.         return None
 917.     tzoffset = None
 918.     tz = tz.upper()
 919.     if tz in _timezones:
 920.         tzoffset = _timezones[tz]
 921.     else:
 922.         try:
 923.             tzoffset = int(tz)
 924.         except ValueError:
 925.             pass
 926.     # Convert a timezone offset into seconds ; -0500 -> -18000
 927.     if tzoffset:
 928.         if tzoffset < 0:
 929.             tzsign = -1
 930.             tzoffset = -tzoffset
 931.         else:
 932.             tzsign = 1
 933.         tzoffset = tzsign * ( (tzoffset//100)*3600 + (tzoffset % 100)*60)
 934.     tuple = (yy, mm, dd, thh, tmm, tss, 0, 0, 0, tzoffset)
 935.     return tuple
 936. 
 937. 
 938. def parsedate(data):
 939.     """Convert a time string to a time tuple."""
 940.     t = parsedate_tz(data)
 941.     if type(t) == type( () ):
 942.         return t[:9]
 943.     else: return t
 944. 
 945. 
 946. def mktime_tz(data):
 947.     """Turn a 10-tuple as returned by parsedate_tz() into a UTC timestamp."""
 948.     if data[9] is None:
 949.         # No zone info, so localtime is better assumption than GMT
 950.         return time.mktime(data[:8] + (-1,))
 951.     else:
 952.         t = time.mktime(data[:8] + (0,))
 953.         return t - data[9] - time.timezone
 954. 
 955. def formatdate(timeval=None):
 956.     """Returns time format preferred for Internet standards.
 957. 
 958.     Sun, 06 Nov 1994 08:49:37 GMT  ; RFC 822, updated by RFC 1123
 959. 
 960.     According to RFC 1123, day and month names must always be in
 961.     English.  If not for that, this code could use strftime().  It
 962.     can't because strftime() honors the locale and could generated
 963.     non-English names.
 964.     """
 965.     if timeval is None:
 966.         timeval = time.time()
 967.     timeval = time.gmtime(timeval)
 968.     return "%s, %02d %s %04d %02d:%02d:%02d GMT" % (
 969.             ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"][timeval[6]],
 970.             timeval[2],
 971.             ["Jan", "Feb", "Mar", "Apr", "May", "Jun",
 972.              "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"][timeval[1]-1],
 973.                                 timeval[0], timeval[3], timeval[4], timeval[5])
 974. 
 975. 
 976. # When used as script, run a small test program.
 977. # The first command line argument must be a filename containing one
 978. # message in RFC-822 format.
 979. 
 980. if __name__ == '__main__':
 981.     import sys, os
 982.     file = os.path.join(os.environ['HOME'], 'Mail/inbox/1')
 983.     if sys.argv[1:]: file = sys.argv[1]
 984.     f = open(file, 'r')
 985.     m = Message(f)
 986.     print 'From:', m.getaddr('from')
 987.     print 'To:', m.getaddrlist('to')
 988.     print 'Subject:', m.getheader('subject')
 989.     print 'Date:', m.getheader('date')
 990.     date = m.getdate_tz('date')
 991.     tz = date[-1]
 992.     date = time.localtime(mktime_tz(date))
 993.     if date:
 994.         print 'ParsedDate:', time.asctime(date),
 995.         hhmmss = tz
 996.         hhmm, ss = divmod(hhmmss, 60)
 997.         hh, mm = divmod(hhmm, 60)
 998.         print "%+03d%02d" % (hh, mm),
 999.         if ss: print ".%02d" % ss,
1000.         print
1001.     else:
1002.         print 'ParsedDate:', None
1003.     m.rewindbody()
1004.     n = 0
1005.     while f.readline():
1006.         n = n + 1
1007.     print 'Lines:', n
1008.     print '-'*70
1009.     print 'len =', len(m)
1010.     if 'Date' in m: print 'Date =', m['Date']
1011.     if 'X-Nonsense' in m: pass
1012.     print 'keys =', m.keys()
1013.     print 'values =', m.values()
1014.     print 'items =', m.items()