cpython/Lib/mimetools.py
1996-08-26 16:40:20 +00:00

194 lines
4.3 KiB
Python

# Various tools used by MIME-reading or MIME-writing programs.
import os
import rfc822
import string
import tempfile
# A derived class of rfc822.Message that knows about MIME headers and
# contains some hooks for decoding encoded and multipart messages.
class Message(rfc822.Message):
def __init__(self, fp, seekable = 1):
rfc822.Message.__init__(self, fp, seekable)
self.encodingheader = \
self.getheader('content-transfer-encoding')
self.typeheader = \
self.getheader('content-type')
self.parsetype()
self.parseplist()
def parsetype(self):
str = self.typeheader
if str == None:
str = 'text/plain'
if ';' in str:
i = string.index(str, ';')
self.plisttext = str[i:]
str = str[:i]
else:
self.plisttext = ''
fields = string.splitfields(str, '/')
for i in range(len(fields)):
fields[i] = string.lower(string.strip(fields[i]))
self.type = string.joinfields(fields, '/')
self.maintype = fields[0]
self.subtype = string.joinfields(fields[1:], '/')
def parseplist(self):
str = self.plisttext
self.plist = []
while str[:1] == ';':
str = str[1:]
if ';' in str:
# XXX Should parse quotes!
end = string.index(str, ';')
else:
end = len(str)
f = str[:end]
if '=' in f:
i = string.index(f, '=')
f = string.lower(string.strip(f[:i])) + \
'=' + string.strip(f[i+1:])
self.plist.append(string.strip(f))
str = str[end:]
def getplist(self):
return self.plist
def getparam(self, name):
name = string.lower(name) + '='
n = len(name)
for p in self.plist:
if p[:n] == name:
return rfc822.unquote(p[n:])
return None
def getencoding(self):
if self.encodingheader == None:
return '7bit'
return string.lower(self.encodingheader)
def gettype(self):
return self.type
def getmaintype(self):
return self.maintype
def getsubtype(self):
return self.subtype
# Utility functions
# -----------------
# Return a random string usable as a multipart boundary.
# The method used is so that it is *very* unlikely that the same
# string of characters will every occur again in the Universe,
# so the caller needn't check the data it is packing for the
# occurrence of the boundary.
#
# The boundary contains dots so you have to quote it in the header.
_prefix = None
def choose_boundary():
global _prefix
import time
import rand
if _prefix == None:
import socket
import os
hostid = socket.gethostbyname(socket.gethostname())
try:
uid = `os.getuid()`
except:
uid = '1'
try:
pid = `os.getpid()`
except:
pid = '1'
seed = `rand.rand()`
_prefix = hostid + '.' + uid + '.' + pid
timestamp = `int(time.time())`
seed = `rand.rand()`
return _prefix + '.' + timestamp + '.' + seed
# Subroutines for decoding some common content-transfer-types
# XXX This requires that uudecode and mmencode are in $PATH
def decode(input, output, encoding):
if decodetab.has_key(encoding):
pipethrough(input, decodetab[encoding], output)
else:
raise ValueError, \
'unknown Content-Transfer-Encoding: %s' % encoding
def encode(input, output, encoding):
if encodetab.has_key(encoding):
pipethrough(input, encodetab[encoding], output)
else:
raise ValueError, \
'unknown Content-Transfer-Encoding: %s' % encoding
uudecode_pipe = '''(
TEMP=/tmp/@uu.$$
sed "s%^begin [0-7][0-7]* .*%begin 600 $TEMP%" | uudecode
cat $TEMP
rm $TEMP
)'''
decodetab = {
'uuencode': uudecode_pipe,
'x-uuencode': uudecode_pipe,
'quoted-printable': 'mmencode -u -q',
'base64': 'mmencode -u -b',
}
encodetab = {
'x-uuencode': 'uuencode tempfile',
'uuencode': 'uuencode tempfile',
'quoted-printable': 'mmencode -q',
'base64': 'mmencode -b',
}
def pipeto(input, command):
pipe = os.popen(command, 'w')
copyliteral(input, pipe)
pipe.close()
def pipethrough(input, command, output):
tempname = tempfile.mktemp()
try:
temp = open(tempname, 'w')
except IOError:
print '*** Cannot create temp file', `tempname`
return
copyliteral(input, temp)
temp.close()
pipe = os.popen(command + ' <' + tempname, 'r')
copybinary(pipe, output)
pipe.close()
os.unlink(tempname)
def copyliteral(input, output):
while 1:
line = input.readline()
if not line: break
output.write(line)
def copybinary(input, output):
BUFSIZE = 8192
while 1:
line = input.read(BUFSIZE)
if not line: break
output.write(line)