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Diffstat (limited to 'Lib/email/utils.py')
-rw-r--r-- | Lib/email/utils.py | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/Lib/email/utils.py b/Lib/email/utils.py new file mode 100644 index 0000000..404cd96 --- /dev/null +++ b/Lib/email/utils.py @@ -0,0 +1,325 @@ +# Copyright (C) 2001-2007 Python Software Foundation +# Author: Barry Warsaw +# Contact: email-sig@python.org + +"""Miscellaneous utilities.""" + +__all__ = [ + 'collapse_rfc2231_value', + 'decode_params', + 'decode_rfc2231', + 'encode_rfc2231', + 'formataddr', + 'formatdate', + 'getaddresses', + 'make_msgid', + 'parseaddr', + 'parsedate', + 'parsedate_tz', + 'unquote', + ] + +import os +import re +import time +import base64 +import random +import socket +import urllib +import warnings +from io import StringIO + +from email._parseaddr import quote +from email._parseaddr import AddressList as _AddressList +from email._parseaddr import mktime_tz + +# We need wormarounds for bugs in these methods in older Pythons (see below) +from email._parseaddr import parsedate as _parsedate +from email._parseaddr import parsedate_tz as _parsedate_tz + +from quopri import decodestring as _qdecode + +# Intrapackage imports +from email.encoders import _bencode, _qencode + +COMMASPACE = ', ' +EMPTYSTRING = '' +UEMPTYSTRING = '' +CRLF = '\r\n' +TICK = "'" + +specialsre = re.compile(r'[][\\()<>@,:;".]') +escapesre = re.compile(r'[][\\()"]') + + + +# Helpers + +def _identity(s): + return s + + +def _bdecode(s): + # We can't quite use base64.encodestring() since it tacks on a "courtesy + # newline". Blech! + if not s: + return s + value = base64.decodestring(s) + if not s.endswith('\n') and value.endswith('\n'): + return value[:-1] + return value + + + +def fix_eols(s): + """Replace all line-ending characters with \r\n.""" + # Fix newlines with no preceding carriage return + s = re.sub(r'(?<!\r)\n', CRLF, s) + # Fix carriage returns with no following newline + s = re.sub(r'\r(?!\n)', CRLF, s) + return s + + + +def formataddr(pair): + """The inverse of parseaddr(), this takes a 2-tuple of the form + (realname, email_address) and returns the string value suitable + for an RFC 2822 From, To or Cc header. + + If the first element of pair is false, then the second element is + returned unmodified. + """ + name, address = pair + if name: + quotes = '' + if specialsre.search(name): + quotes = '"' + name = escapesre.sub(r'\\\g<0>', name) + return '%s%s%s <%s>' % (quotes, name, quotes, address) + return address + + + +def getaddresses(fieldvalues): + """Return a list of (REALNAME, EMAIL) for each fieldvalue.""" + all = COMMASPACE.join(fieldvalues) + a = _AddressList(all) + return a.addresslist + + + +ecre = re.compile(r''' + =\? # literal =? + (?P<charset>[^?]*?) # non-greedy up to the next ? is the charset + \? # literal ? + (?P<encoding>[qb]) # either a "q" or a "b", case insensitive + \? # literal ? + (?P<atom>.*?) # non-greedy up to the next ?= is the atom + \?= # literal ?= + ''', re.VERBOSE | re.IGNORECASE) + + + +def formatdate(timeval=None, localtime=False, usegmt=False): + """Returns a date string as specified by RFC 2822, e.g.: + + Fri, 09 Nov 2001 01:08:47 -0000 + + Optional timeval if given is a floating point time value as accepted by + gmtime() and localtime(), otherwise the current time is used. + + Optional localtime is a flag that when True, interprets timeval, and + returns a date relative to the local timezone instead of UTC, properly + taking daylight savings time into account. + + Optional argument usegmt means that the timezone is written out as + an ascii string, not numeric one (so "GMT" instead of "+0000"). This + is needed for HTTP, and is only used when localtime==False. + """ + # Note: we cannot use strftime() because that honors the locale and RFC + # 2822 requires that day and month names be the English abbreviations. + if timeval is None: + timeval = time.time() + if localtime: + now = time.localtime(timeval) + # Calculate timezone offset, based on whether the local zone has + # daylight savings time, and whether DST is in effect. + if time.daylight and now[-1]: + offset = time.altzone + else: + offset = time.timezone + hours, minutes = divmod(abs(offset), 3600) + # Remember offset is in seconds west of UTC, but the timezone is in + # minutes east of UTC, so the signs differ. + if offset > 0: + sign = '-' + else: + sign = '+' + zone = '%s%02d%02d' % (sign, hours, minutes // 60) + else: + now = time.gmtime(timeval) + # Timezone offset is always -0000 + if usegmt: + zone = 'GMT' + else: + zone = '-0000' + return '%s, %02d %s %04d %02d:%02d:%02d %s' % ( + ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'][now[6]], + now[2], + ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', + 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec'][now[1] - 1], + now[0], now[3], now[4], now[5], + zone) + + + +def make_msgid(idstring=None): + """Returns a string suitable for RFC 2822 compliant Message-ID, e.g: + + <20020201195627.33539.96671@nightshade.la.mastaler.com> + + Optional idstring if given is a string used to strengthen the + uniqueness of the message id. + """ + timeval = time.time() + utcdate = time.strftime('%Y%m%d%H%M%S', time.gmtime(timeval)) + pid = os.getpid() + randint = random.randrange(100000) + if idstring is None: + idstring = '' + else: + idstring = '.' + idstring + idhost = socket.getfqdn() + msgid = '<%s.%s.%s%s@%s>' % (utcdate, pid, randint, idstring, idhost) + return msgid + + + +# These functions are in the standalone mimelib version only because they've +# subsequently been fixed in the latest Python versions. We use this to worm +# around broken older Pythons. +def parsedate(data): + if not data: + return None + return _parsedate(data) + + +def parsedate_tz(data): + if not data: + return None + return _parsedate_tz(data) + + +def parseaddr(addr): + addrs = _AddressList(addr).addresslist + if not addrs: + return '', '' + return addrs[0] + + +# rfc822.unquote() doesn't properly de-backslash-ify in Python pre-2.3. +def unquote(str): + """Remove quotes from a string.""" + if len(str) > 1: + if str.startswith('"') and str.endswith('"'): + return str[1:-1].replace('\\\\', '\\').replace('\\"', '"') + if str.startswith('<') and str.endswith('>'): + return str[1:-1] + return str + + + +# RFC2231-related functions - parameter encoding and decoding +def decode_rfc2231(s): + """Decode string according to RFC 2231""" + parts = s.split(TICK, 2) + if len(parts) <= 2: + return None, None, s + return parts + + +def encode_rfc2231(s, charset=None, language=None): + """Encode string according to RFC 2231. + + If neither charset nor language is given, then s is returned as-is. If + charset is given but not language, the string is encoded using the empty + string for language. + """ + import urllib + s = urllib.quote(s, safe='') + if charset is None and language is None: + return s + if language is None: + language = '' + return "%s'%s'%s" % (charset, language, s) + + +rfc2231_continuation = re.compile(r'^(?P<name>\w+)\*((?P<num>[0-9]+)\*?)?$') + +def decode_params(params): + """Decode parameters list according to RFC 2231. + + params is a sequence of 2-tuples containing (param name, string value). + """ + # Copy params so we don't mess with the original + params = params[:] + new_params = [] + # Map parameter's name to a list of continuations. The values are a + # 3-tuple of the continuation number, the string value, and a flag + # specifying whether a particular segment is %-encoded. + rfc2231_params = {} + name, value = params.pop(0) + new_params.append((name, value)) + while params: + name, value = params.pop(0) + if name.endswith('*'): + encoded = True + else: + encoded = False + value = unquote(value) + mo = rfc2231_continuation.match(name) + if mo: + name, num = mo.group('name', 'num') + if num is not None: + num = int(num) + rfc2231_params.setdefault(name, []).append((num, value, encoded)) + else: + new_params.append((name, '"%s"' % quote(value))) + if rfc2231_params: + for name, continuations in rfc2231_params.items(): + value = [] + extended = False + # Sort by number + continuations.sort() + # And now append all values in numerical order, converting + # %-encodings for the encoded segments. If any of the + # continuation names ends in a *, then the entire string, after + # decoding segments and concatenating, must have the charset and + # language specifiers at the beginning of the string. + for num, s, encoded in continuations: + if encoded: + s = urllib.unquote(s) + extended = True + value.append(s) + value = quote(EMPTYSTRING.join(value)) + if extended: + charset, language, value = decode_rfc2231(value) + new_params.append((name, (charset, language, '"%s"' % value))) + else: + new_params.append((name, '"%s"' % value)) + return new_params + +def collapse_rfc2231_value(value, errors='replace', + fallback_charset='us-ascii'): + if not isinstance(value, tuple) or len(value) != 3: + return unquote(value) + # While value comes to us as a unicode string, we need it to be a bytes + # object. We do not want bytes() normal utf-8 decoder, we want a straight + # interpretation of the string as character bytes. + charset, language, text = value + rawbytes = bytes(ord(c) for c in text) + try: + return str(rawbytes, charset, errors) + except LookupError: + # charset is not a known codec. + return unquote(text) |