Source code for ntpath

# 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",
           "getatime","getctime", "islink","exists","lexists","isdir","isfile",
           "ismount", "expanduser","expandvars","normpath","abspath",
           "samefile", "sameopenfile", "samestat", "commonpath"]

def _get_bothseps(path):
    if isinstance(path, bytes):
        return b'\\/'
        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()
            return s.replace('/', '\\').lower()
    except (TypeError, AttributeError):
        if not isinstance(s, (bytes, str)):
            raise TypeError("normcase() argument must be str or bytes, "
                            "not %r" % s.__class__.__name__) from None

# 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)
    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':'
        sep = '\\'
        seps = '\\/'
        colon = ':'
        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
            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
                # 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)

# 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':'
            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'.')
        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.

[docs]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, 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: 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 'HOME' in os.environ: userhome = os.environ['HOME'] elif '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 # - '$$' is translated into '$' # - '%%' is translated into '%' if '%%' are not seen in %var1%%var2% # - ${varname} is accepted. # - $varname is accepted. # - %varname% is accepted. # - varnames can be made out of letters, digits and the characters '_-' # (though is not verified in the ${varname} and %varname% cases) # XXX With COMMAND.COM you can use any characters in a variable name, # XXX except '^|<>='. def expandvars(path): """Expand shell variables of the forms $var, ${var} and %var%. Unknown variables are left unchanged.""" path = os.fspath(path) if isinstance(path, bytes): if b'$' not in path and b'%' not in path: return path import string varchars = bytes(string.ascii_letters + string.digits + '_-', 'ascii') quote = b'\'' percent = b'%' brace = b'{' rbrace = b'}' dollar = b'$' environ = getattr(os, 'environb', None) else: if '$' not in path and '%' not in path: return path import string varchars = string.ascii_letters + string.digits + '_-' quote = '\'' percent = '%' brace = '{' rbrace = '}' dollar = '$' environ = os.environ res = path[:0] index = 0 pathlen = len(path) while index < pathlen: c = path[index:index+1] if c == quote: # no expansion within single quotes path = path[index + 1:] pathlen = len(path) try: index = path.index(c) res += c + path[:index + 1] except ValueError: res += c + path index = pathlen - 1 elif c == percent: # variable or '%' if path[index + 1:index + 2] == percent: res += c index += 1 else: path = path[index+1:] pathlen = len(path) try: index = path.index(percent) except ValueError: res += percent + path index = pathlen - 1 else: var = path[:index] try: if environ is None: value = os.fsencode(os.environ[os.fsdecode(var)]) else: value = environ[var] except KeyError: value = percent + var + percent res += value elif c == dollar: # variable or '$$' if path[index + 1:index + 2] == dollar: res += c index += 1 elif path[index + 1:index + 2] == brace: path = path[index+2:] pathlen = len(path) try: index = path.index(rbrace) except ValueError: res += dollar + brace + path index = pathlen - 1 else: var = path[:index] try: if environ is None: value = os.fsencode(os.environ[os.fsdecode(var)]) else: value = environ[var] except KeyError: value = dollar + brace + var + rbrace res += value else: var = path[:0] index += 1 c = path[index:index + 1] while c and c in varchars: var += c index += 1 c = path[index:index + 1] try: if environ is None: value = os.fsencode(os.environ[os.fsdecode(var)]) else: value = environ[var] except KeyError: value = dollar + var res += value if c: index -= 1 else: res += c index += 1 return res # 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 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) # realpath is a no-op on systems without islink support realpath = abspath # 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 # determine if two files are in fact the same file try: # GetFinalPathNameByHandle is available starting with Windows 6.0. # Windows XP and non-Windows OS'es will mock _getfinalpathname. if sys.getwindowsversion()[:2] >= (6, 0): from nt import _getfinalpathname else: raise ImportError except (AttributeError, ImportError): # On Windows XP and earlier, two files are the same if their absolute # pathnames are the same. # Non-Windows operating systems fake this method with an XP # approximation. def _getfinalpathname(f): return normcase(abspath(f)) 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