"""Mailcap file handling. See RFC 1524."""
__all__ = ["getcaps","findmatch"]
def lineno_sort_key(entry):
# Sort in ascending order, with unspecified entries at the end
return 0, entry['lineno']
_find_unsafe = re.compile(r'[^\xa1-\U0010FFFF\w@+=:,./-]').search
class UnsafeMailcapInput(Warning):
"""Warning raised when refusing unsafe input"""
# Part 1: top-level interface.
"""Return a dictionary containing the mailcap database.
The dictionary maps a MIME type (in all lowercase, e.g. 'text/plain')
to a list of dictionaries corresponding to mailcap entries. The list
collects all the entries for that MIME type from all available mailcap
files. Each dictionary contains key-value pairs for that MIME type,
where the viewing command is stored with the key "view".
for mailcap in listmailcapfiles():
morecaps, lineno = _readmailcapfile(fp, lineno)
for key, value in morecaps.items():
caps[key] = caps[key] + value
"""Return a list of all mailcap files found on the system."""
# This is mostly a Unix thing, but we use the OS path separator anyway
if 'MAILCAPS' in os.environ:
pathstr = os.environ['MAILCAPS']
mailcaps = pathstr.split(os.pathsep)
home = os.environ['HOME']
# Don't bother with getpwuid()
mailcaps = [home + '/.mailcap', '/etc/mailcap',
'/usr/etc/mailcap', '/usr/local/etc/mailcap']
"""Read a mailcap file and return a dictionary keyed by MIME type."""
warnings.warn('readmailcapfile is deprecated, use getcaps instead',
caps, _ = _readmailcapfile(fp, None)
def _readmailcapfile(fp, lineno):
"""Read a mailcap file and return a dictionary keyed by MIME type.
Each MIME type is mapped to an entry consisting of a list of
dictionaries; the list will contain more than one such dictionary
if a given MIME type appears more than once in the mailcap file.
Each dictionary contains key-value pairs for that MIME type, where
the viewing command is stored with the key "view".
# Ignore comments and blank lines
if line[0] == '#' or line.strip() == '':
# Join continuation lines
while nextline[-2:] == '\\\n':
if not nextline: nextline = '\n'
line = line[:-2] + nextline
key, fields = parseline(line)
fields['lineno'] = lineno
for j in range(len(types)):
types[j] = types[j].strip()
key = '/'.join(types).lower()
"""Parse one entry in a mailcap file and return a dictionary.
The viewing command is stored as the value with the key "view",
and the rest of the fields produce key-value pairs in the dict.
field, i = parsefield(line, i, n)
key, view, rest = fields[0], fields[1], fields[2:]
fvalue = field[i+1:].strip()
def parsefield(line, i, n):
"""Separate one key-value pair in a mailcap entry."""
return line[start:i].strip(), i
# Part 3: using the database.
def findmatch(caps, MIMEtype, key='view', filename="/dev/null", plist=[]):
"""Find a match for a mailcap entry.
Return a tuple containing the command line, and the mailcap entry
used; (None, None) if no match is found. This may invoke the
'test' command of several matching entries before deciding which
if _find_unsafe(filename):
msg = "Refusing to use mailcap with filename %r. Use a safe temporary filename." % (filename,)
warnings.warn(msg, UnsafeMailcapInput)
entries = lookup(caps, MIMEtype, key)
# XXX This code should somehow check for the needsterminal flag.
test = subst(e['test'], filename, plist)
if test and os.system(test) != 0:
command = subst(e[key], MIMEtype, filename, plist)
def lookup(caps, MIMEtype, key=None):
entries = entries + caps[MIMEtype]
MIMEtypes = MIMEtype.split('/')
MIMEtype = MIMEtypes[0] + '/*'
entries = entries + caps[MIMEtype]
entries = [e for e in entries if key in e]
entries = sorted(entries, key=lineno_sort_key)
def subst(field, MIMEtype, filename, plist=[]):
# XXX Actually, this is Unix-specific
c = field[i:i+1]; i = i+1
if _find_unsafe(MIMEtype):
msg = "Refusing to substitute MIME type %r into a shell command." % (MIMEtype,)
warnings.warn(msg, UnsafeMailcapInput)
while i < n and field[i] != '}':
param = findparam(name, plist)
msg = "Refusing to substitute parameter %r (%s) into a shell command" % (param, name)
warnings.warn(msg, UnsafeMailcapInput)
# %n == number of parts if type is multipart/*
# %F == list of alternating type and filename for parts
def findparam(name, plist):
name = name.lower() + '='
if p[:n].lower() == name:
for i in range(1, len(sys.argv), 2):
print("usage: mailcap [MIMEtype file] ...")
command, e = findmatch(caps, MIMEtype, 'view', file)
print("No viewer found for", type)
print("Executing:", command)
print("Exit status:", sts)
for fn in listmailcapfiles(): print("\t" + fn)
if not caps: caps = getcaps()
print("Mailcap entries:")
print(" %-15s" % k, e[k])
if __name__ == '__main__':
It is recommended that you Edit text format, this type of Fix handles quite a lot in one request
