# 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"]

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 '^|<>='.

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 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.
 realpath = abspath
else:
 def _readlink_deep(path):
 # 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 OSError 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):
 # 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
 # 67: ERROR_BAD_NET_NAME (implies remote server unavailable)
 # 87: ERROR_INVALID_PARAMETER
 # 123: ERROR_INVALID_NAME
 # 1920: ERROR_CANT_ACCESS_FILE
 # 1921: ERROR_CANT_RESOLVE_FILENAME (implies unfollowable symlink)
 allowed_winerror = 1, 2, 3, 5, 21, 32, 50, 67, 87, 123, 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 OSError 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)
 if new_path != path:
 return join(new_path, tail) if tail else new_path
 except OSError:
 # 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):
 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 not had_prefix and not isabs(path):
 path = join(cwd, path)
 try:
 path = _getfinalpathname(path)
 initial_winerror = 0
 except OSError as ex:
 initial_winerror = ex.winerror
 path = _getfinalpathname_nonstrict(path)
 # 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