"""
This module is based on a rox module (LGPL):
http://cvs.sourceforge.net/viewcvs.py/rox/ROX-Lib2/python/rox/mime.py?rev=1.21&view=log
This module provides access to the shared MIME database.
types is a dictionary of all known MIME types, indexed by the type name, e.g.
types['application/x-python']
Applications can install information about MIME types by storing an
XML file as <MIME>/packages/<application>.xml and running the
update-mime-database command, which is provided by the freedesktop.org
shared mime database package.
See http://www.freedesktop.org/standards/shared-mime-info-spec/ for
information about the format of these files.
(based on version 0.13)
"""
import os
import stat
import sys
import fnmatch
from xdg import BaseDirectory
import xdg.Locale
from xml.dom import minidom, XML_NAMESPACE
from collections import defaultdict
FREE_NS = 'http://www.freedesktop.org/standards/shared-mime-info'
types = {} # Maps MIME names to type objects
exts = None # Maps extensions to types
globs = None # List of (glob, type) pairs
literals = None # Maps liternal names to types
magic = None
PY3 = (sys.version_info[0] >= 3)
def _get_node_data(node):
"""Get text of XML node"""
return ''.join([n.nodeValue for n in node.childNodes]).strip()
def lookup(media, subtype = None):
"""Get the MIMEtype object for this type, creating a new one if needed.
The name can either be passed as one part ('text/plain'), or as two
('text', 'plain').
"""
if subtype is None and '/' in media:
media, subtype = media.split('/', 1)
if (media, subtype) not in types:
types[(media, subtype)] = MIMEtype(media, subtype)
return types[(media, subtype)]
class MIMEtype:
"""Type holding data about a MIME type"""
def __init__(self, media, subtype):
"Don't use this constructor directly; use mime.lookup() instead."
assert media and '/' not in media
assert subtype and '/' not in subtype
assert (media, subtype) not in types
self.media = media
self.subtype = subtype
self._comment = None
def _load(self):
"Loads comment for current language. Use get_comment() instead."
resource = os.path.join('mime', self.media, self.subtype + '.xml')
for path in BaseDirectory.load_data_paths(resource):
doc = minidom.parse(path)
if doc is None:
continue
for comment in doc.documentElement.getElementsByTagNameNS(FREE_NS, 'comment'):
lang = comment.getAttributeNS(XML_NAMESPACE, 'lang') or 'en'
goodness = 1 + (lang in xdg.Locale.langs)
if goodness > self._comment[0]:
self._comment = (goodness, _get_node_data(comment))
if goodness == 2: return
# FIXME: add get_icon method
def get_comment(self):
"""Returns comment for current language, loading it if needed."""
# Should we ever reload?
if self._comment is None:
self._comment = (0, str(self))
self._load()
return self._comment[1]
def canonical(self):
"""Returns the canonical MimeType object if this is an alias."""
update_cache()
s = str(self)
if s in aliases:
return lookup(aliases[s])
return self
def inherits_from(self):
"""Returns a set of Mime types which this inherits from."""
update_cache()
return set(lookup(t) for t in inheritance[str(self)])
def __str__(self):
return self.media + '/' + self.subtype
def __repr__(self):
return '<%s: %s>' % (self, self._comment or '(comment not loaded)')
class MagicRule:
def __init__(self, f):
self.next=None
self.prev=None
#print line
ind=b''
while True:
c=f.read(1)
if c == b'>':
break
ind+=c
if not ind:
self.nest=0
else:
self.nest=int(ind.decode('ascii'))
start = b''
while True:
c = f.read(1)
if c == b'=':
break
start += c
self.start = int(start.decode('ascii'))
hb=f.read(1)
lb=f.read(1)
self.lenvalue = ord(lb)+(ord(hb)<<8)
self.value = f.read(self.lenvalue)
c = f.read(1)
if c == b'&':
self.mask = f.read(self.lenvalue)
c = f.read(1)
else:
self.mask=None
if c == b'~':
w = b''
while c!=b'+' and c!=b'\n':
c=f.read(1)
if c==b'+' or c==b'\n':
break
w+=c
self.word=int(w.decode('ascii'))
else:
self.word=1
if c==b'+':
r=b''
while c!=b'\n':
c=f.read(1)
if c==b'\n':
break
r+=c
#print r
self.range = int(r.decode('ascii'))
else:
self.range = 1
if c != b'\n':
raise ValueError('Malformed MIME magic line')
def getLength(self):
return self.start+self.lenvalue+self.range
def appendRule(self, rule):
if self.nest<rule.nest:
self.next=rule
rule.prev=self
elif self.prev:
self.prev.appendRule(rule)
def match(self, buffer):
if self.match0(buffer):
if self.next:
return self.next.match(buffer)
return True
def match0(self, buffer):
l=len(buffer)
for o in range(self.range):
s=self.start+o
e=s+self.lenvalue
if l<e:
return False
if self.mask:
test=''
for i in range(self.lenvalue):
if PY3:
c = buffer[s+i] & self.mask[i]
else:
c = ord(buffer[s+i]) & ord(self.mask[i])
test += chr(c)
else:
test = buffer[s:e]
if test==self.value:
return True
def __repr__(self):
return '<MagicRule %d>%d=[%d]%r&%r~%d+%d>' % (self.nest,
self.start,
self.lenvalue,
self.value,
self.mask,
self.word,
self.range)
class MagicType:
def __init__(self, mtype):
self.mtype=mtype
self.top_rules=[]
self.last_rule=None
def getLine(self, f):
nrule=MagicRule(f)
if nrule.nest and self.last_rule:
self.last_rule.appendRule(nrule)
else:
self.top_rules.append(nrule)
self.last_rule=nrule
return nrule
def match(self, buffer):
for rule in self.top_rules:
if rule.match(buffer):
return self.mtype
def __repr__(self):
return '<MagicType %s>' % self.mtype
class MagicDB:
def __init__(self):
self.types={} # Indexed by priority, each entry is a list of type rules
self.maxlen=0
def mergeFile(self, fname):
with open(fname, 'rb') as f:
line = f.readline()
if line != b'MIME-Magic\0\n':
raise IOError('Not a MIME magic file')
while True:
shead = f.readline().decode('ascii')
#print shead
if not shead:
break
if shead[0] != '[' or shead[-2:] != ']\n':
raise ValueError('Malformed section heading')
pri, tname = shead[1:-2].split(':')
#print shead[1:-2]
pri = int(pri)
mtype = lookup(tname)
try:
ents = self.types[pri]
except:
ents = []
self.types[pri] = ents
magictype = MagicType(mtype)
#print tname
#rline=f.readline()
c=f.read(1)
f.seek(-1, 1)
while c and c != b'[':
rule=magictype.getLine(f)
#print rule
if rule and rule.getLength() > self.maxlen:
self.maxlen = rule.getLength()
c = f.read(1)
f.seek(-1, 1)
ents.append(magictype)
#self.types[pri]=ents
if not c:
break
def match_data(self, data, max_pri=100, min_pri=0):
for priority in sorted(self.types.keys(), reverse=True):
#print priority, max_pri, min_pri
if priority > max_pri:
continue
if priority < min_pri:
break
for type in self.types[priority]:
m=type.match(data)
if m:
return m
def match(self, path, max_pri=100, min_pri=0):
try:
with open(path, 'rb') as f:
buf = f.read(self.maxlen)
return self.match_data(buf, max_pri, min_pri)
except:
pass
def __repr__(self):
return '<MagicDB %s>' % self.types
# Some well-known types
text = lookup('text', 'plain')
inode_block = lookup('inode', 'blockdevice')
inode_char = lookup('inode', 'chardevice')
inode_dir = lookup('inode', 'directory')
inode_fifo = lookup('inode', 'fifo')
inode_socket = lookup('inode', 'socket')
inode_symlink = lookup('inode', 'symlink')
inode_door = lookup('inode', 'door')
app_exe = lookup('application', 'executable')
_cache_uptodate = False
def _cache_database():
global exts, globs, literals, magic, aliases, inheritance, _cache_uptodate
_cache_uptodate = True
exts = {} # Maps extensions to types
globs = [] # List of (glob, type) pairs
literals = {} # Maps literal names to types
aliases = {} # Maps alias Mime types to canonical names
inheritance = defaultdict(set) # Maps to sets of parent mime types.
magic = MagicDB()
def _import_glob_file(path):
"""Loads name matching information from a MIME directory."""
with open(path) as f:
for line in f:
if line.startswith('#'): continue
line = line[:-1]
type_name, pattern = line.split(':', 1)
mtype = lookup(type_name)
if pattern.startswith('*.'):
rest = pattern[2:]
if not ('*' in rest or '[' in rest or '?' in rest):
if rest not in exts:
exts[rest] = mtype
continue
if '*' in pattern or '[' in pattern or '?' in pattern:
globs.append((pattern, mtype))
else:
literals[pattern] = mtype
for path in BaseDirectory.load_data_paths(os.path.join('mime', 'globs')):
_import_glob_file(path)
for path in BaseDirectory.load_data_paths(os.path.join('mime', 'magic')):
magic.mergeFile(path)
# Sort globs by length
globs.sort(key=lambda x: len(x[0]) )
# Load aliases
for path in BaseDirectory.load_data_paths(os.path.join('mime', 'aliases')):
with open(path, 'r') as f:
for line in f:
alias, canonical = line.strip().split(None, 1)
aliases[alias] = canonical
# Load subclasses
for path in BaseDirectory.load_data_paths(os.path.join('mime', 'subclasses')):
with open(path, 'r') as f:
for line in f:
sub, parent = line.strip().split(None, 1)
inheritance[sub].add(parent)
def update_cache():
if not _cache_uptodate:
_cache_database()
def get_type_by_name(path):
"""Returns type of file by its name, or None if not known"""
update_cache()
leaf = os.path.basename(path)
if leaf in literals:
return literals[leaf]
lleaf = leaf.lower()
if lleaf in literals:
return literals[lleaf]
ext = leaf
while 1:
p = ext.find('.')
if p < 0: break
ext = ext[p + 1:]
if ext in exts:
return exts[ext]
ext = lleaf
while 1:
p = ext.find('.')
if p < 0: break
ext = ext[p+1:]
if ext in exts:
return exts[ext]
for (glob, mime_type) in globs:
if fnmatch.fnmatch(leaf, glob):
return mime_type
if fnmatch.fnmatch(lleaf, glob):
return mime_type
return None
def get_type_by_contents(path, max_pri=100, min_pri=0):
"""Returns type of file by its contents, or None if not known"""
update_cache()
return magic.match(path, max_pri, min_pri)
def get_type_by_data(data, max_pri=100, min_pri=0):
"""Returns type of the data, which should be bytes."""
update_cache()
return magic.match_data(data, max_pri, min_pri)
def get_type(path, follow=True, name_pri=100):
"""Returns type of file indicated by path.
path :
pathname to check (need not exist)
follow :
when reading file, follow symbolic links
name_pri :
Priority to do name matches. 100=override magic
This tries to use the contents of the file, and falls back to the name. It
can also handle special filesystem objects like directories and sockets.
"""
update_cache()
try:
if follow:
st = os.stat(path)
else:
st = os.lstat(path)
except:
t = get_type_by_name(path)
return t or text
if stat.S_ISREG(st.st_mode):
t = get_type_by_contents(path, min_pri=name_pri)
if not t: t = get_type_by_name(path)
if not t: t = get_type_by_contents(path, max_pri=name_pri)
if t is None:
if stat.S_IMODE(st.st_mode) & 0o111:
return app_exe
else:
return text
return t
elif stat.S_ISDIR(st.st_mode): return inode_dir
elif stat.S_ISCHR(st.st_mode): return inode_char
elif stat.S_ISBLK(st.st_mode): return inode_block
elif stat.S_ISFIFO(st.st_mode): return inode_fifo
elif stat.S_ISLNK(st.st_mode): return inode_symlink
elif stat.S_ISSOCK(st.st_mode): return inode_socket
return inode_door
def install_mime_info(application, package_file):
"""Copy 'package_file' as ``~/.local/share/mime/packages/<application>.xml.``
If package_file is None, install ``<app_dir>/<application>.xml``.
If already installed, does nothing. May overwrite an existing
file with the same name (if the contents are different)"""
application += '.xml'
new_data = open(package_file).read()
# See if the file is already installed
package_dir = os.path.join('mime', 'packages')
resource = os.path.join(package_dir, application)
for x in BaseDirectory.load_data_paths(resource):
try:
old_data = open(x).read()
except:
continue
if old_data == new_data:
return # Already installed
global _cache_uptodate
_cache_uptodate = False
# Not already installed; add a new copy
# Create the directory structure...
new_file = os.path.join(BaseDirectory.save_data_path(package_dir), application)
# Write the file...
open(new_file, 'w').write(new_data)
# Update the database...
command = 'update-mime-database'
if os.spawnlp(os.P_WAIT, command, command, BaseDirectory.save_data_path('mime')):
os.unlink(new_file)
raise Exception("The '%s' command returned an error code!\n" \
"Make sure you have the freedesktop.org shared MIME package:\n" \
"http://standards.freedesktop.org/shared-mime-info/" % command)