JezK
Edit File: ntpath.py
# Module 'ntpath' -- common operations on WinNT/Win95 pathnames """Common pathname manipulations, WindowsNT/95 version. Instead of importing this module directly, import os and refer to this module as os.path. """ # strings representing various path-related bits and pieces # These are primarily for export; internally, they are hardcoded. # Should be set before imports for resolving cyclic dependency. curdir = '.' pardir = '..' extsep = '.' sep = '\\' pathsep = ';' altsep = '/' defpath = '.;C:\\bin' devnull = 'nul' import os import sys import stat import genericpath from genericpath import * __all__ = ["normcase","isabs","join","splitdrive","split","splitext", "basename","dirname","commonprefix","getsize","getmtime", "getatime","getctime", "islink","exists","lexists","isdir","isfile", "ismount", "expanduser","expandvars","normpath","abspath", "curdir","pardir","sep","pathsep","defpath","altsep", "extsep","devnull","realpath","supports_unicode_filenames","relpath", "samefile", "sameopenfile", "samestat", "commonpath", "ALLOW_MISSING"] def _get_bothseps(path): if isinstance(path, bytes): return b'\\/' else: return '\\/' # Normalize the case of a pathname and map slashes to backslashes. # Other normalizations (such as optimizing '../' away) are not done # (this is done by normpath). def normcase(s): """Normalize case of pathname. Makes all characters lowercase and all slashes into backslashes.""" s = os.fspath(s) if isinstance(s, bytes): return s.replace(b'/', b'\\').lower() else: return s.replace('/', '\\').lower() # Return whether a path is absolute. # Trivial in Posix, harder on Windows. # For Windows it is absolute if it starts with a slash or backslash (current # volume), or if a pathname after the volume-letter-and-colon or UNC-resource # starts with a slash or backslash. def isabs(s): """Test whether a path is absolute""" s = os.fspath(s) # Paths beginning with \\?\ are always absolute, but do not # necessarily contain a drive. if isinstance(s, bytes): if s.replace(b'/', b'\\').startswith(b'\\\\?\\'): return True else: if s.replace('/', '\\').startswith('\\\\?\\'): return True s = splitdrive(s)[1] return len(s) > 0 and s[0] in _get_bothseps(s) # Join two (or more) paths. def join(path, *paths): path = os.fspath(path) if isinstance(path, bytes): sep = b'\\' seps = b'\\/' colon = b':' else: sep = '\\' seps = '\\/' colon = ':' try: if not paths: path[:0] + sep #23780: Ensure compatible data type even if p is null. result_drive, result_path = splitdrive(path) for p in map(os.fspath, paths): p_drive, p_path = splitdrive(p) if p_path and p_path[0] in seps: # Second path is absolute if p_drive or not result_drive: result_drive = p_drive result_path = p_path continue elif p_drive and p_drive != result_drive: if p_drive.lower() != result_drive.lower(): # Different drives => ignore the first path entirely result_drive = p_drive result_path = p_path continue # Same drive in different case result_drive = p_drive # Second path is relative to the first if result_path and result_path[-1] not in seps: result_path = result_path + sep result_path = result_path + p_path ## add separator between UNC and non-absolute path if (result_path and result_path[0] not in seps and result_drive and result_drive[-1:] != colon): return result_drive + sep + result_path return result_drive + result_path except (TypeError, AttributeError, BytesWarning): genericpath._check_arg_types('join', path, *paths) raise # Split a path in a drive specification (a drive letter followed by a # colon) and the path specification. # It is always true that drivespec + pathspec == p def splitdrive(p): """Split a pathname into drive/UNC sharepoint and relative path specifiers. Returns a 2-tuple (drive_or_unc, path); either part may be empty. If you assign result = splitdrive(p) It is always true that: result[0] + result[1] == p If the path contained a drive letter, drive_or_unc will contain everything up to and including the colon. e.g. splitdrive("c:/dir") returns ("c:", "/dir") If the path contained a UNC path, the drive_or_unc will contain the host name and share up to but not including the fourth directory separator character. e.g. splitdrive("//host/computer/dir") returns ("//host/computer", "/dir") Paths cannot contain both a drive letter and a UNC path. """ p = os.fspath(p) if len(p) >= 2: if isinstance(p, bytes): sep = b'\\' altsep = b'/' colon = b':' else: sep = '\\' altsep = '/' colon = ':' normp = p.replace(altsep, sep) if (normp[0:2] == sep*2) and (normp[2:3] != sep): # is a UNC path: # vvvvvvvvvvvvvvvvvvvv drive letter or UNC path # \\machine\mountpoint\directory\etc\... # directory ^^^^^^^^^^^^^^^ index = normp.find(sep, 2) if index == -1: return p[:0], p index2 = normp.find(sep, index + 1) # a UNC path can't have two slashes in a row # (after the initial two) if index2 == index + 1: return p[:0], p if index2 == -1: index2 = len(p) return p[:index2], p[index2:] if normp[1:2] == colon: return p[:2], p[2:] return p[:0], p # Split a path in head (everything up to the last '/') and tail (the # rest). After the trailing '/' is stripped, the invariant # join(head, tail) == p holds. # The resulting head won't end in '/' unless it is the root. def split(p): """Split a pathname. Return tuple (head, tail) where tail is everything after the final slash. Either part may be empty.""" p = os.fspath(p) seps = _get_bothseps(p) d, p = splitdrive(p) # set i to index beyond p's last slash i = len(p) while i and p[i-1] not in seps: i -= 1 head, tail = p[:i], p[i:] # now tail has no slashes # remove trailing slashes from head, unless it's all slashes head = head.rstrip(seps) or head return d + head, tail # Split a path in root and extension. # The extension is everything starting at the last dot in the last # pathname component; the root is everything before that. # It is always true that root + ext == p. def splitext(p): p = os.fspath(p) if isinstance(p, bytes): return genericpath._splitext(p, b'\\', b'/', b'.') else: return genericpath._splitext(p, '\\', '/', '.') splitext.__doc__ = genericpath._splitext.__doc__ # Return the tail (basename) part of a path. def basename(p): """Returns the final component of a pathname""" return split(p)[1] # Return the head (dirname) part of a path. def dirname(p): """Returns the directory component of a pathname""" return split(p)[0] # Is a path a symbolic link? # This will always return false on systems where os.lstat doesn't exist. def islink(path): """Test whether a path is a symbolic link. This will always return false for Windows prior to 6.0. """ try: st = os.lstat(path) except (OSError, ValueError, AttributeError): return False return stat.S_ISLNK(st.st_mode) # Being true for dangling symbolic links is also useful. def lexists(path): """Test whether a path exists. Returns True for broken symbolic links""" try: st = os.lstat(path) except (OSError, ValueError): return False return True # Is a path a mount point? # Any drive letter root (eg c:\) # Any share UNC (eg \\server\share) # Any volume mounted on a filesystem folder # # No one method detects all three situations. Historically we've lexically # detected drive letter roots and share UNCs. The canonical approach to # detecting mounted volumes (querying the reparse tag) fails for the most # common case: drive letter roots. The alternative which uses GetVolumePathName # fails if the drive letter is the result of a SUBST. try: from nt import _getvolumepathname except ImportError: _getvolumepathname = None def ismount(path): """Test whether a path is a mount point (a drive root, the root of a share, or a mounted volume)""" path = os.fspath(path) seps = _get_bothseps(path) path = abspath(path) root, rest = splitdrive(path) if root and root[0] in seps: return (not rest) or (rest in seps) if rest in seps: return True if _getvolumepathname: return path.rstrip(seps) == _getvolumepathname(path).rstrip(seps) else: return False # Expand paths beginning with '~' or '~user'. # '~' means $HOME; '~user' means that user's home directory. # If the path doesn't begin with '~', or if the user or $HOME is unknown, # the path is returned unchanged (leaving error reporting to whatever # function is called with the expanded path as argument). # See also module 'glob' for expansion of *, ? and [...] in pathnames. # (A function should also be defined to do full *sh-style environment # variable expansion.) def expanduser(path): """Expand ~ and ~user constructs. If user or $HOME is unknown, do nothing.""" path = os.fspath(path) if isinstance(path, bytes): tilde = b'~' else: tilde = '~' if not path.startswith(tilde): return path i, n = 1, len(path) while i < n and path[i] not in _get_bothseps(path): i += 1 if 'USERPROFILE' in os.environ: userhome = os.environ['USERPROFILE'] elif not 'HOMEPATH' in os.environ: return path else: try: drive = os.environ['HOMEDRIVE'] except KeyError: drive = '' userhome = join(drive, os.environ['HOMEPATH']) if isinstance(path, bytes): userhome = os.fsencode(userhome) if i != 1: #~user userhome = join(dirname(userhome), path[1:i]) return userhome + path[i:] # Expand paths containing shell variable substitutions. # The following rules apply: # - no expansion within single quotes # - '$$' is translated into '$' # - '%%' is translated into '%' if '%%' are not seen in %var1%%var2% # - ${varname} is accepted. # - $varname is accepted. # - %varname% is accepted. # - varnames can be made out of letters, digits and the characters '_-' # (though is not verified in the ${varname} and %varname% cases) # XXX With COMMAND.COM you can use any characters in a variable name, # XXX except '^|<>='. _varpattern = r"'[^']*'?|%(%|[^%]*%?)|\$(\$|[-\w]+|\{[^}]*\}?)" _varsub = None _varsubb = None def expandvars(path): """Expand shell variables of the forms $var, ${var} and %var%. Unknown variables are left unchanged.""" path = os.fspath(path) global _varsub, _varsubb if isinstance(path, bytes): if b'$' not in path and b'%' not in path: return path if not _varsubb: import re _varsubb = re.compile(_varpattern.encode(), re.ASCII).sub sub = _varsubb percent = b'%' brace = b'{' rbrace = b'}' dollar = b'$' environ = getattr(os, 'environb', None) else: if '$' not in path and '%' not in path: return path if not _varsub: import re _varsub = re.compile(_varpattern, re.ASCII).sub sub = _varsub percent = '%' brace = '{' rbrace = '}' dollar = '$' environ = os.environ def repl(m): lastindex = m.lastindex if lastindex is None: return m[0] name = m[lastindex] if lastindex == 1: if name == percent: return name if not name.endswith(percent): return m[0] name = name[:-1] else: if name == dollar: return name if name.startswith(brace): if not name.endswith(rbrace): return m[0] name = name[1:-1] try: if environ is None: return os.fsencode(os.environ[os.fsdecode(name)]) else: return environ[name] except KeyError: return m[0] return sub(repl, path) # Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A\B. # Previously, this function also truncated pathnames to 8+3 format, # but as this module is called "ntpath", that's obviously wrong! def normpath(path): """Normalize path, eliminating double slashes, etc.""" path = os.fspath(path) if isinstance(path, bytes): sep = b'\\' altsep = b'/' curdir = b'.' pardir = b'..' special_prefixes = (b'\\\\.\\', b'\\\\?\\') else: sep = '\\' altsep = '/' curdir = '.' pardir = '..' special_prefixes = ('\\\\.\\', '\\\\?\\') if path.startswith(special_prefixes): # in the case of paths with these prefixes: # \\.\ -> device names # \\?\ -> literal paths # do not do any normalization, but return the path # unchanged apart from the call to os.fspath() return path path = path.replace(altsep, sep) prefix, path = splitdrive(path) # collapse initial backslashes if path.startswith(sep): prefix += sep path = path.lstrip(sep) comps = path.split(sep) i = 0 while i < len(comps): if not comps[i] or comps[i] == curdir: del comps[i] elif comps[i] == pardir: if i > 0 and comps[i-1] != pardir: del comps[i-1:i+1] i -= 1 elif i == 0 and prefix.endswith(sep): del comps[i] else: i += 1 else: i += 1 # If the path is now empty, substitute '.' if not prefix and not comps: comps.append(curdir) return prefix + sep.join(comps) def _abspath_fallback(path): """Return the absolute version of a path as a fallback function in case `nt._getfullpathname` is not available or raises OSError. See bpo-31047 for more. """ path = os.fspath(path) if not isabs(path): if isinstance(path, bytes): cwd = os.getcwdb() else: cwd = os.getcwd() path = join(cwd, path) return normpath(path) # Return an absolute path. try: from nt import _getfullpathname except ImportError: # not running on Windows - mock up something sensible abspath = _abspath_fallback else: # use native Windows method on Windows def abspath(path): """Return the absolute version of a path.""" try: return normpath(_getfullpathname(path)) except (OSError, ValueError): return _abspath_fallback(path) try: from nt import _getfinalpathname, readlink as _nt_readlink except ImportError: # realpath is a no-op on systems without _getfinalpathname support. def realpath(path, *, strict=False): return abspath(path) else: def _readlink_deep(path, ignored_error=OSError): # These error codes indicate that we should stop reading links and # return the path we currently have. # 1: ERROR_INVALID_FUNCTION # 2: ERROR_FILE_NOT_FOUND # 3: ERROR_DIRECTORY_NOT_FOUND # 5: ERROR_ACCESS_DENIED # 21: ERROR_NOT_READY (implies drive with no media) # 32: ERROR_SHARING_VIOLATION (probably an NTFS paging file) # 50: ERROR_NOT_SUPPORTED (implies no support for reparse points) # 67: ERROR_BAD_NET_NAME (implies remote server unavailable) # 87: ERROR_INVALID_PARAMETER # 4390: ERROR_NOT_A_REPARSE_POINT # 4392: ERROR_INVALID_REPARSE_DATA # 4393: ERROR_REPARSE_TAG_INVALID allowed_winerror = 1, 2, 3, 5, 21, 32, 50, 67, 87, 4390, 4392, 4393 seen = set() while normcase(path) not in seen: seen.add(normcase(path)) try: old_path = path path = _nt_readlink(path) # Links may be relative, so resolve them against their # own location if not isabs(path): # If it's something other than a symlink, we don't know # what it's actually going to be resolved against, so # just return the old path. if not islink(old_path): path = old_path break path = normpath(join(dirname(old_path), path)) except ignored_error as ex: if ex.winerror in allowed_winerror: break raise except ValueError: # Stop on reparse points that are not symlinks break return path def _getfinalpathname_nonstrict(path, ignored_error=OSError): # These error codes indicate that we should stop resolving the path # and return the value we currently have. # 1: ERROR_INVALID_FUNCTION # 2: ERROR_FILE_NOT_FOUND # 3: ERROR_DIRECTORY_NOT_FOUND # 5: ERROR_ACCESS_DENIED # 21: ERROR_NOT_READY (implies drive with no media) # 32: ERROR_SHARING_VIOLATION (probably an NTFS paging file) # 50: ERROR_NOT_SUPPORTED # 53: ERROR_BAD_NETPATH # 65: ERROR_NETWORK_ACCESS_DENIED # 67: ERROR_BAD_NET_NAME (implies remote server unavailable) # 87: ERROR_INVALID_PARAMETER # 123: ERROR_INVALID_NAME # 161: ERROR_BAD_PATHNAME # 1920: ERROR_CANT_ACCESS_FILE # 1921: ERROR_CANT_RESOLVE_FILENAME (implies unfollowable symlink) allowed_winerror = 1, 2, 3, 5, 21, 32, 50, 53, 65, 67, 87, 123, 161, 1920, 1921 # Non-strict algorithm is to find as much of the target directory # as we can and join the rest. tail = '' while path: try: path = _getfinalpathname(path) return join(path, tail) if tail else path except ignored_error as ex: if ex.winerror not in allowed_winerror: raise try: # The OS could not resolve this path fully, so we attempt # to follow the link ourselves. If we succeed, join the tail # and return. new_path = _readlink_deep(path, ignored_error=ignored_error) if new_path != path: return join(new_path, tail) if tail else new_path except ignored_error: # If we fail to readlink(), let's keep traversing pass path, name = split(path) # TODO (bpo-38186): Request the real file name from the directory # entry using FindFirstFileW. For now, we will return the path # as best we have it if path and not name: return path + tail tail = join(name, tail) if tail else name return tail def realpath(path, *, strict=False): path = normpath(path) if isinstance(path, bytes): prefix = b'\\\\?\\' unc_prefix = b'\\\\?\\UNC\\' new_unc_prefix = b'\\\\' cwd = os.getcwdb() # bpo-38081: Special case for realpath(b'nul') if normcase(path) == normcase(os.fsencode(devnull)): return b'\\\\.\\NUL' else: prefix = '\\\\?\\' unc_prefix = '\\\\?\\UNC\\' new_unc_prefix = '\\\\' cwd = os.getcwd() # bpo-38081: Special case for realpath('nul') if normcase(path) == normcase(devnull): return '\\\\.\\NUL' had_prefix = path.startswith(prefix) if strict is ALLOW_MISSING: ignored_error = FileNotFoundError strict = True elif strict: ignored_error = () else: ignored_error = OSError if not had_prefix and not isabs(path): path = join(cwd, path) try: path = _getfinalpathname(path) initial_winerror = 0 except ignored_error as ex: initial_winerror = ex.winerror path = _getfinalpathname_nonstrict(path, ignored_error=ignored_error) # The path returned by _getfinalpathname will always start with \\?\ - # strip off that prefix unless it was already provided on the original # path. if not had_prefix and path.startswith(prefix): # For UNC paths, the prefix will actually be \\?\UNC\ # Handle that case as well. if path.startswith(unc_prefix): spath = new_unc_prefix + path[len(unc_prefix):] else: spath = path[len(prefix):] # Ensure that the non-prefixed path resolves to the same path try: if _getfinalpathname(spath) == path: path = spath except OSError as ex: # If the path does not exist and originally did not exist, then # strip the prefix anyway. if ex.winerror == initial_winerror: path = spath return path # Win9x family and earlier have no Unicode filename support. supports_unicode_filenames = (hasattr(sys, "getwindowsversion") and sys.getwindowsversion()[3] >= 2) def relpath(path, start=None): """Return a relative version of a path""" path = os.fspath(path) if isinstance(path, bytes): sep = b'\\' curdir = b'.' pardir = b'..' else: sep = '\\' curdir = '.' pardir = '..' if start is None: start = curdir if not path: raise ValueError("no path specified") start = os.fspath(start) try: start_abs = abspath(normpath(start)) path_abs = abspath(normpath(path)) start_drive, start_rest = splitdrive(start_abs) path_drive, path_rest = splitdrive(path_abs) if normcase(start_drive) != normcase(path_drive): raise ValueError("path is on mount %r, start on mount %r" % ( path_drive, start_drive)) start_list = [x for x in start_rest.split(sep) if x] path_list = [x for x in path_rest.split(sep) if x] # Work out how much of the filepath is shared by start and path. i = 0 for e1, e2 in zip(start_list, path_list): if normcase(e1) != normcase(e2): break i += 1 rel_list = [pardir] * (len(start_list)-i) + path_list[i:] if not rel_list: return curdir return join(*rel_list) except (TypeError, ValueError, AttributeError, BytesWarning, DeprecationWarning): genericpath._check_arg_types('relpath', path, start) raise # Return the longest common sub-path of the sequence of paths given as input. # The function is case-insensitive and 'separator-insensitive', i.e. if the # only difference between two paths is the use of '\' versus '/' as separator, # they are deemed to be equal. # # However, the returned path will have the standard '\' separator (even if the # given paths had the alternative '/' separator) and will have the case of the # first path given in the sequence. Additionally, any trailing separator is # stripped from the returned path. def commonpath(paths): """Given a sequence of path names, returns the longest common sub-path.""" if not paths: raise ValueError('commonpath() arg is an empty sequence') paths = tuple(map(os.fspath, paths)) if isinstance(paths[0], bytes): sep = b'\\' altsep = b'/' curdir = b'.' else: sep = '\\' altsep = '/' curdir = '.' try: drivesplits = [splitdrive(p.replace(altsep, sep).lower()) for p in paths] split_paths = [p.split(sep) for d, p in drivesplits] try: isabs, = set(p[:1] == sep for d, p in drivesplits) except ValueError: raise ValueError("Can't mix absolute and relative paths") from None # Check that all drive letters or UNC paths match. The check is made only # now otherwise type errors for mixing strings and bytes would not be # caught. if len(set(d for d, p in drivesplits)) != 1: raise ValueError("Paths don't have the same drive") drive, path = splitdrive(paths[0].replace(altsep, sep)) common = path.split(sep) common = [c for c in common if c and c != curdir] split_paths = [[c for c in s if c and c != curdir] for s in split_paths] s1 = min(split_paths) s2 = max(split_paths) for i, c in enumerate(s1): if c != s2[i]: common = common[:i] break else: common = common[:len(s1)] prefix = drive + sep if isabs else drive return prefix + sep.join(common) except (TypeError, AttributeError): genericpath._check_arg_types('commonpath', *paths) raise try: # The genericpath.isdir implementation uses os.stat and checks the mode # attribute to tell whether or not the path is a directory. # This is overkill on Windows - just pass the path to GetFileAttributes # and check the attribute from there. from nt import _isdir as isdir except ImportError: # Use genericpath.isdir as imported above. pass