C 有没有路径处理方面的内置库或三方库(GCC/MINGW/LINUX/WINDOWS)
本帖最后由 hrpzcf 于 2021-11-25 14:39 编辑路径分割：路径，文件名，扩展名
路径处理：获取上一级路径，等等
为了有动力学习C，用C实现一个以前用Python写的小工具，才发现什么都要自己写，轮子都不知道要怎么找，太累了{:5_109:}
这些都是自己写的范畴吧，哪来现成的库 wp231957 发表于 2021-11-25 14:09
这些都是自己写的范畴吧，哪来现成的库
自己写也不是不行，就是写完可能还要不少测试来发现问题 up hrpzcf 发表于 2021-11-25 14:33
自己写也不是不行，就是写完可能还要不少测试来发现问题
把python的os.path的几个相应函数的源码拿来改改不就好了~~ C语言的我没找到，C++可以用boost.filesystem（在c++17中被收入标准库） lightninng 发表于 2021-11-26 02:41
把python的os.path的几个相应函数的源码拿来改改不就好了~~
os.path的具体实现好像是在C源码里的，说实话我在Python项目源代码包找了半天没找到在哪，所以我还是自己写了，linux路径处理还好，windows的就很麻烦，各种出乎意料的路径 hrpzcf 发表于 2021-11-27 09:26
os.path的具体实现好像是在C源码里的，说实话我在Python项目源代码包找了半天没找到在哪，所以我还是自己 ...
我这边的路径是：
/usr/lib/python3.9/posixpath.py
"""Common operations on Posix pathnames.
Instead of importing this module directly, import os and refer to
this module as os.path.The "os.path" name is an alias for this
module on Posix systems; on other systems (e.g. Windows),
os.path provides the same operations in a manner specific to that
platform, and is an alias to another module (e.g. ntpath).
Some of this can actually be useful on non-Posix systems too, e.g.
for manipulation of the pathname component of URLs.
"""
# 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 = ':'
defpath = '/bin:/usr/bin'
altsep = None
devnull = '/dev/null'
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",
"samefile","sameopenfile","samestat",
"curdir","pardir","sep","pathsep","defpath","altsep","extsep",
"devnull","realpath","supports_unicode_filenames","relpath",
"commonpath"]
def _get_sep(path):
if isinstance(path, bytes):
return b'/'
else:
return '/'
# Normalize the case of a pathname.Trivial in Posix, string.lower on Mac.
# On MS-DOS this may also turn slashes into backslashes; however, other
# normalizations (such as optimizing '../' away) are not allowed
# (another function should be defined to do that).
def normcase(s):
"""Normalize case of pathname.Has no effect under Posix"""
return os.fspath(s)
# Return whether a path is absolute.
# Trivial in Posix, harder on the Mac or MS-DOS.
def isabs(s):
"""Test whether a path is absolute"""
s = os.fspath(s)
sep = _get_sep(s)
return s.startswith(sep)
# Join pathnames.
# Ignore the previous parts if a part is absolute.
# Insert a '/' unless the first part is empty or already ends in '/'.
def join(a, *p):
"""Join two or more pathname components, inserting '/' as needed.
If any component is an absolute path, all previous path components
will be discarded.An empty last part will result in a path that
ends with a separator."""
a = os.fspath(a)
sep = _get_sep(a)
path = a
try:
if not p:
path[:0] + sep#23780: Ensure compatible data type even if p is null.
for b in map(os.fspath, p):
if b.startswith(sep):
path = b
elif not path or path.endswith(sep):
path += b
else:
path += sep + b
except (TypeError, AttributeError, BytesWarning):
genericpath._check_arg_types('join', a, *p)
raise
return path
# Split a path in head (everything up to the last '/') and tail (the
# rest).If the path ends in '/', tail will be empty.If there is no
# '/' in the path, headwill be empty.
# Trailing '/'es are stripped from head unless it is the root.
def split(p):
"""Split a pathname.Returns tuple "(head, tail)" where "tail" is
everything after the final slash.Either part may be empty."""
p = os.fspath(p)
sep = _get_sep(p)
i = p.rfind(sep) + 1
head, tail = p[:i], p
if head and head != sep*len(head):
head = head.rstrip(sep)
return 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):
sep = b'/'
extsep = b'.'
else:
sep = '/'
extsep = '.'
return genericpath._splitext(p, sep, None, extsep)
splitext.__doc__ = genericpath._splitext.__doc__
# Split a pathname into a drive specification and the rest of the
# path.Useful on DOS/Windows/NT; on Unix, the drive is always empty.
def splitdrive(p):
"""Split a pathname into drive and path. On Posix, drive is always
empty."""
p = os.fspath(p)
return p[:0], p
# Return the tail (basename) part of a path, same as split(path).
def basename(p):
"""Returns the final component of a pathname"""
p = os.fspath(p)
sep = _get_sep(p)
i = p.rfind(sep) + 1
return p
# Return the head (dirname) part of a path, same as split(path).
def dirname(p):
"""Returns the directory component of a pathname"""
p = os.fspath(p)
sep = _get_sep(p)
i = p.rfind(sep) + 1
head = p[:i]
if head and head != sep*len(head):
head = head.rstrip(sep)
return head
# 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"""
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:
os.lstat(path)
except (OSError, ValueError):
return False
return True
# Is a path a mount point?
# (Does this work for all UNIXes?Is it even guaranteed to work by Posix?)
def ismount(path):
"""Test whether a path is a mount point"""
try:
s1 = os.lstat(path)
except (OSError, ValueError):
# It doesn't exist -- so not a mount point. :-)
return False
else:
# A symlink can never be a mount point
if stat.S_ISLNK(s1.st_mode):
return False
if isinstance(path, bytes):
parent = join(path, b'..')
else:
parent = join(path, '..')
parent = realpath(parent)
try:
s2 = os.lstat(parent)
except (OSError, ValueError):
return False
dev1 = s1.st_dev
dev2 = s2.st_dev
if dev1 != dev2:
return True # path/.. on a different device as path
ino1 = s1.st_ino
ino2 = s2.st_ino
if ino1 == ino2:
return True # path/.. is the same i-node as path
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 constructions.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
sep = _get_sep(path)
i = path.find(sep, 1)
if i < 0:
i = len(path)
if i == 1:
if 'HOME' not in os.environ:
import pwd
try:
userhome = pwd.getpwuid(os.getuid()).pw_dir
except KeyError:
# bpo-10496: if the current user identifier doesn't exist in the
# password database, return the path unchanged
return path
else:
userhome = os.environ['HOME']
else:
import pwd
name = path
if isinstance(name, bytes):
name = str(name, 'ASCII')
try:
pwent = pwd.getpwnam(name)
except KeyError:
# bpo-10496: if the user name from the path doesn't exist in the
# password database, return the path unchanged
return path
userhome = pwent.pw_dir
if isinstance(path, bytes):
userhome = os.fsencode(userhome)
root = b'/'
else:
root = '/'
userhome = userhome.rstrip(root)
return (userhome + path) or root
# Expand paths containing shell variable substitutions.
# This expands the forms $variable and ${variable} only.
# Non-existent variables are left unchanged.
_varprog = None
_varprogb = None
def expandvars(path):
"""Expand shell variables of form $var and ${var}.Unknown variables
are left unchanged."""
path = os.fspath(path)
global _varprog, _varprogb
if isinstance(path, bytes):
if b'$' not in path:
return path
if not _varprogb:
import re
_varprogb = re.compile(br'\$(\w+|\{[^}]*\})', re.ASCII)
search = _varprogb.search
start = b'{'
end = b'}'
environ = getattr(os, 'environb', None)
else:
if '$' not in path:
return path
if not _varprog:
import re
_varprog = re.compile(r'\$(\w+|\{[^}]*\})', re.ASCII)
search = _varprog.search
start = '{'
end = '}'
environ = os.environ
i = 0
while True:
m = search(path, i)
if not m:
break
i, j = m.span(0)
name = m.group(1)
if name.startswith(start) and name.endswith(end):
name = name
try:
if environ is None:
value = os.fsencode(os.environ)
else:
value = environ
except KeyError:
i = j
else:
tail = path
path = path[:i] + value
i = len(path)
path += tail
return path
# Normalize a path, e.g. A//B, A/./B and A/foo/../B all become A/B.
# It should be understood that this may change the meaning of the path
# if it contains symbolic links!
def normpath(path):
"""Normalize path, eliminating double slashes, etc."""
path = os.fspath(path)
if isinstance(path, bytes):
sep = b'/'
empty = b''
dot = b'.'
dotdot = b'..'
else:
sep = '/'
empty = ''
dot = '.'
dotdot = '..'
if path == empty:
return dot
initial_slashes = path.startswith(sep)
# POSIX allows one or two initial slashes, but treats three or more
# as single slash.
# (see http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap04.html#tag_04_13)
if (initial_slashes and
path.startswith(sep*2) and not path.startswith(sep*3)):
initial_slashes = 2
comps = path.split(sep)
new_comps = []
for comp in comps:
if comp in (empty, dot):
continue
if (comp != dotdot or (not initial_slashes and not new_comps) or
(new_comps and new_comps[-1] == dotdot)):
new_comps.append(comp)
elif new_comps:
new_comps.pop()
comps = new_comps
path = sep.join(comps)
if initial_slashes:
path = sep*initial_slashes + path
return path or dot
def abspath(path):
"""Return an absolute path."""
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 a canonical path (i.e. the absolute location of a file on the
# filesystem).
def realpath(filename):
"""Return the canonical path of the specified filename, eliminating any
symbolic links encountered in the path."""
filename = os.fspath(filename)
path, ok = _joinrealpath(filename[:0], filename, {})
return abspath(path)
# Join two paths, normalizing and eliminating any symbolic links
# encountered in the second path.
def _joinrealpath(path, rest, seen):
if isinstance(path, bytes):
sep = b'/'
curdir = b'.'
pardir = b'..'
else:
sep = '/'
curdir = '.'
pardir = '..'
if isabs(rest):
rest = rest
path = sep
while rest:
name, _, rest = rest.partition(sep)
if not name or name == curdir:
# current dir
continue
if name == pardir:
# parent dir
if path:
path, name = split(path)
if name == pardir:
path = join(path, pardir, pardir)
else:
path = pardir
continue
newpath = join(path, name)
if not islink(newpath):
path = newpath
continue
# Resolve the symbolic link
if newpath in seen:
# Already seen this path
path = seen
if path is not None:
# use cached value
continue
# The symlink is not resolved, so we must have a symlink loop.
# Return already resolved part + rest of the path unchanged.
return join(newpath, rest), False
seen = None # not resolved symlink
path, ok = _joinrealpath(path, os.readlink(newpath), seen)
if not ok:
return join(path, rest), False
seen = path # resolved symlink
return path, True
supports_unicode_filenames = (sys.platform == 'darwin')
def relpath(path, start=None):
"""Return a relative version of a path"""
if not path:
raise ValueError("no path specified")
path = os.fspath(path)
if isinstance(path, bytes):
curdir = b'.'
sep = b'/'
pardir = b'..'
else:
curdir = '.'
sep = '/'
pardir = '..'
if start is None:
start = curdir
else:
start = os.fspath(start)
try:
start_list =
path_list =
# Work out how much of the filepath is shared by start and path.
i = len(commonprefix())
rel_list = * (len(start_list)-i) + path_list
if not rel_list:
return curdir
return join(*rel_list)
except (TypeError, 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 paths are not normalized before comparing them (this is the
# responsibility of the caller). 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, bytes):
sep = b'/'
curdir = b'.'
else:
sep = '/'
curdir = '.'
try:
split_paths =
try:
isabs, = set(p[:1] == sep for p in paths)
except ValueError:
raise ValueError("Can't mix absolute and relative paths") from None
split_paths = [ for s in split_paths]
s1 = min(split_paths)
s2 = max(split_paths)
common = s1
for i, c in enumerate(s1):
if c != s2:
common = s1[:i]
break
prefix = sep if isabs else sep[:0]
return prefix + sep.join(common)
except (TypeError, AttributeError):
genericpath._check_arg_types('commonpath', *paths)
raise
windows 的在这里
/usr/lib/python3.9/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"]
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)
return len(s) > 0 and s 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 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 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 + result == 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 == sep*2) and (normp != 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
if normp == colon:
return p[:2], p
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 not in seps:
i -= 1
head, tail = p[:i], p# 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)
# Return the head (dirname) part of a path.
def dirname(p):
"""Returns the directory component of a pathname"""
return split(p)
# 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 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 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)
return userhome + path
# Expand paths containing shell variable substitutions.
# The following rules apply:
# - no expansion within single quotes
# - '$$' is translated into '$'
# - '%%' is translated into '%' if '%%' are not seen in %var1%%var2%
# - ${varname} is accepted.
# - $varname is accepted.
# - %varname% is accepted.
# - varnames can be made out of letters, digits and the characters '_-'
# (though is not verified in the ${varname} and %varname% cases)
# XXX With COMMAND.COM you can use any characters in a variable name,
# XXX except '^|<>='.
def expandvars(path):
"""Expand shell variables of the forms $var, ${var} and %var%.
Unknown variables are left unchanged."""
path = os.fspath(path)
if isinstance(path, bytes):
if b'$' not in path and b'%' not in path:
return path
import string
varchars = bytes(string.ascii_letters + string.digits + '_-', 'ascii')
quote = b'\''
percent = b'%'
brace = b'{'
rbrace = b'}'
dollar = b'$'
environ = getattr(os, 'environb', None)
else:
if '$' not in path and '%' not in path:
return path
import string
varchars = string.ascii_letters + string.digits + '_-'
quote = '\''
percent = '%'
brace = '{'
rbrace = '}'
dollar = '$'
environ = os.environ
res = path[:0]
index = 0
pathlen = len(path)
while index < pathlen:
c = path
if c == quote: # no expansion within single quotes
path = path
pathlen = len(path)
try:
index = path.index(c)
res += c + path[:index + 1]
except ValueError:
res += c + path
index = pathlen - 1
elif c == percent:# variable or '%'
if path == percent:
res += c
index += 1
else:
path = path
pathlen = len(path)
try:
index = path.index(percent)
except ValueError:
res += percent + path
index = pathlen - 1
else:
var = path[:index]
try:
if environ is None:
value = os.fsencode(os.environ)
else:
value = environ
except KeyError:
value = percent + var + percent
res += value
elif c == dollar:# variable or '$$'
if path == dollar:
res += c
index += 1
elif path == brace:
path = path
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)
else:
value = environ
except KeyError:
value = dollar + brace + var + rbrace
res += value
else:
var = path[:0]
index += 1
c = path
while c and c in varchars:
var += c
index += 1
c = path
try:
if environ is None:
value = os.fsencode(os.environ)
else:
value = environ
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 or comps == curdir:
del comps
elif comps == pardir:
if i > 0 and comps != pardir:
del comps
i -= 1
elif i == 0 and prefix.endswith(sep):
del comps
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
else:
spath = path
# 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() >= 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 =
path_list =
# 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 = * (len(start_list)-i) + path_list
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, bytes):
sep = b'\\'
altsep = b'/'
curdir = b'.'
else:
sep = '\\'
altsep = '/'
curdir = '.'
try:
drivesplits =
split_paths =
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.replace(altsep, sep))
common = path.split(sep)
common =
split_paths = [ for s in split_paths]
s1 = min(split_paths)
s2 = max(split_paths)
for i, c in enumerate(s1):
if c != s2:
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
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