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.
python类lstat()的实例源码
def copymode(src, dst, *, follow_symlinks=True):
"""Copy mode bits from src to dst.
If follow_symlinks is not set, symlinks aren't followed if and only
if both `src` and `dst` are symlinks. If `lchmod` isn't available
(e.g. Linux) this method does nothing.
"""
if not follow_symlinks and os.path.islink(src) and os.path.islink(dst):
if hasattr(os, 'lchmod'):
stat_func, chmod_func = os.lstat, os.lchmod
else:
return
elif hasattr(os, 'chmod'):
stat_func, chmod_func = os.stat, os.chmod
else:
return
st = stat_func(src)
chmod_func(dst, stat.S_IMODE(st.st_mode))
def copytree(src, dst, symlinks = False, ignore = None):
if not os.path.exists(dst):
os.makedirs(dst)
shutil.copystat(src, dst)
lst = os.listdir(src)
if ignore:
excl = ignore(src, lst)
lst = [x for x in lst if x not in excl]
for item in lst:
s = os.path.join(src, item)
d = os.path.join(dst, item)
if symlinks and os.path.islink(s):
if os.path.lexists(d):
os.remove(d)
os.symlink(os.readlink(s), d)
try:
st = os.lstat(s)
mode = stat.S_IMODE(st.st_mode)
os.lchmod(d, mode)
except:
pass # lchmod not available
elif os.path.isdir(s):
copytree(s, d, symlinks, ignore)
else:
shutil.copy2(s, d)
def is_partition(self, dev):
"""
Check whether a given device path is a partition or a full disk.
"""
if not os.path.exists(dev):
raise Error('device not found', dev)
dev = os.path.realpath(dev)
if not stat.S_ISBLK(os.lstat(dev).st_mode):
raise Error('not a block device', dev)
name = self._get_dev_name(dev)
if os.path.exists(os.path.join('/sys/block', name)):
return False
# make sure it is a partition of something else
for basename in os.listdir('/sys/block'):
if os.path.exists(os.path.join('/sys/block', basename, name)):
return True
raise Error('not a disk or partition', dev)
def getattr(self, path, fh=None):
full_path = self.join_path(path)
st = os.lstat(full_path)
attr = dict((key, getattr(st, key))
for key in (
'st_atime',
'st_ctime',
'st_gid',
'st_mode',
'st_mtime',
'st_nlink',
'st_size',
'st_uid'
)
)
return attr
def getattr(self, path, fh=None):
full_path = self.join_path(path)
st = os.lstat(full_path)
attr = dict((key, getattr(st, key))
for key in (
'st_atime',
'st_ctime',
'st_gid',
'st_mode',
'st_mtime',
'st_nlink',
'st_size',
'st_uid'
)
)
return attr
def getattr(self, path, fh=None):
full_path = self._full_path(path)
st = os.lstat(full_path)
attr = dict((key, getattr(st, key))
for key in (
'st_atime',
'st_ctime',
'st_gid',
'st_mode',
'st_mtime',
'st_nlink',
'st_size',
'st_uid'
)
)
return attr
def find_ext_volume_global_trash(volume_root):
# from [2] Trash directories (1) check for a .Trash dir with the right
# permissions set.
trash_dir = op.join(volume_root, TOPDIR_TRASH)
if not op.exists(trash_dir):
return None
mode = os.lstat(trash_dir).st_mode
# vol/.Trash must be a directory, cannot be a symlink, and must have the
# sticky bit set.
if not op.isdir(trash_dir) or op.islink(trash_dir) or not (mode & stat.S_ISVTX):
return None
trash_dir = op.join(trash_dir, str(uid))
try:
check_create(trash_dir)
except OSError:
return None
return trash_dir
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.
def copymode(src, dst, *, follow_symlinks=True):
"""Copy mode bits from src to dst.
If follow_symlinks is not set, symlinks aren't followed if and only
if both `src` and `dst` are symlinks. If `lchmod` isn't available
(e.g. Linux) this method does nothing.
"""
if not follow_symlinks and os.path.islink(src) and os.path.islink(dst):
if hasattr(os, 'lchmod'):
stat_func, chmod_func = os.lstat, os.lchmod
else:
return
elif hasattr(os, 'chmod'):
stat_func, chmod_func = os.stat, os.chmod
else:
return
st = stat_func(src)
chmod_func(dst, stat.S_IMODE(st.st_mode))
def stat(self, follow_symlinks=True):
if follow_symlinks:
if self._stat is None:
if self.is_symlink():
# It's a symlink, call link-following stat()
self._stat = stat(self.path)
else:
# Not a symlink, stat is same as lstat value
if self._lstat is None:
self._lstat = find_data_to_stat(self._find_data)
self._stat = self._lstat
return self._stat
else:
if self._lstat is None:
# Lazily convert to stat object, because it's slow
# in Python, and often we only need is_dir() etc
self._lstat = find_data_to_stat(self._find_data)
return self._lstat
def map_id(path, map_uid, map_gid):
"""
Remapping ownership of all files inside a container's rootfs.
map_gid and map_uid: Contain integers in a list with format:
[<start>, <target>, <count>]
"""
if map_uid:
uid_opts = get_mapping_opts(map_uid)
if map_gid:
gid_opts = get_mapping_opts(map_gid)
for root, _ignore, files in os.walk(os.path.realpath(path)):
for name in [root] + files:
file_path = os.path.join(root, name)
stat_info = os.lstat(file_path)
old_uid = stat_info.st_uid
old_gid = stat_info.st_gid
new_uid = get_map_id(old_uid, uid_opts) if map_uid else -1
new_gid = get_map_id(old_gid, gid_opts) if map_gid else -1
os.lchown(file_path, new_uid, new_gid)
def find_ext_volume_global_trash(volume_root):
# from [2] Trash directories (1) check for a .Trash dir with the right
# permissions set.
trash_dir = op.join(volume_root, TOPDIR_TRASH)
if not op.exists(trash_dir):
return None
mode = os.lstat(trash_dir).st_mode
# vol/.Trash must be a directory, cannot be a symlink, and must have the
# sticky bit set.
if not op.isdir(trash_dir) or op.islink(trash_dir) or not (mode & stat.S_ISVTX):
return None
trash_dir = op.join(trash_dir, str(uid))
try:
check_create(trash_dir)
except OSError:
return None
return trash_dir
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 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 lexists(path):
"""Test whether a path exists. Returns True for broken symbolic links"""
try:
os.lstat(path)
except OSError:
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:
# 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:
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 _rmtree_unsafe(path, onerror):
try:
if os.path.islink(path):
# symlinks to directories are forbidden, see bug #1669
raise OSError("Cannot call rmtree on a symbolic link")
except OSError:
onerror(os.path.islink, path, sys.exc_info())
# can't continue even if onerror hook returns
return
names = []
try:
names = os.listdir(path)
except OSError:
onerror(os.listdir, path, sys.exc_info())
for name in names:
fullname = os.path.join(path, name)
try:
mode = os.lstat(fullname).st_mode
except OSError:
mode = 0
if stat.S_ISDIR(mode):
_rmtree_unsafe(fullname, onerror)
else:
try:
os.unlink(fullname)
except OSError:
onerror(os.unlink, fullname, sys.exc_info())
try:
os.rmdir(path)
except OSError:
onerror(os.rmdir, path, sys.exc_info())
# Version using fd-based APIs to protect against races
def dirname(p):
"""Returns the directory component of a pathname"""
i = p.rfind('/') + 1
head = p[:i]
if head and head != '/'*len(head):
head = head.rstrip('/')
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 (os.error, 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 os.error:
return False
return True
# Are two filenames really pointing to the same file?
def sameopenfile(fp1, fp2):
"""Test whether two open file objects reference the same file"""
s1 = os.fstat(fp1)
s2 = os.fstat(fp2)
return samestat(s1, s2)
# Are two stat buffers (obtained from stat, fstat or lstat)
# describing the same file?
def ismount(path):
"""Test whether a path is a mount point"""
if islink(path):
# A symlink can never be a mount point
return False
try:
s1 = os.lstat(path)
s2 = os.lstat(join(path, '..'))
except os.error:
return False # It doesn't exist -- so not a mount point :-)
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
# Directory tree walk.
# For each directory under top (including top itself, but excluding
# '.' and '..'), func(arg, dirname, filenames) is called, where
# dirname is the name of the directory and filenames is the list
# of files (and subdirectories etc.) in the directory.
# The func may modify the filenames list, to implement a filter,
# or to impose a different order of visiting.
def islink(s):
"""Return true if the pathname refers to a symbolic link."""
try:
import Carbon.File
return Carbon.File.ResolveAliasFile(s, 0)[2]
except:
return False
# Is `stat`/`lstat` a meaningful difference on the Mac? This is safe in any
# case.
def lexists(path):
"""Test whether a path exists. Returns True for broken symbolic links"""
try:
st = os.lstat(path)
except os.error:
return False
return True
def __hashDir(self, prefix, path=b''):
entries = []
try:
dirEntries = os.listdir(os.path.join(prefix, path if path else b'.'))
except OSError as e:
logging.getLogger(__name__).warning("Cannot list directory: %s", str(e))
dirEntries = []
for f in dirEntries:
e = os.path.join(path, f)
try:
s = os.lstat(os.path.join(prefix, e))
if stat.S_ISDIR(s.st_mode):
# skip useless directories
if f in self.__ignoreDirs: continue
# add training '/' for directores for correct sorting
f = f + os.fsencode(os.path.sep)
else:
# skip useless files
if f in DirHasher.IGNORE_FILES: continue
entries.append((e, f, s))
except OSError as err:
logging.getLogger(__name__).warning("Cannot stat '%s': %s", e, str(err))
entries = sorted(entries, key=lambda x: x[1])
dirList = [
(struct.pack("=L", s.st_mode) + self.__hashEntry(prefix, e, s) + f)
for (e, f, s) in entries
]
dirBlob = b"".join(dirList)
m = hashlib.sha1()
m.update(dirBlob)
return m.digest()
def hashPath(self, path):
path = os.fsencode(path)
try:
s = os.lstat(path)
except OSError as err:
logging.getLogger(__name__).warning("Cannot stat '%s': %s", path, str(err))
return b''
self.__index.open()
try:
return self.__hashEntry(path, b'', s)
finally:
self.__index.close()
def _get_default_cache_dir(self):
def _unsafe_dir():
raise RuntimeError('Cannot determine safe temp directory. You '
'need to explicitly provide one.')
tmpdir = tempfile.gettempdir()
# On windows the temporary directory is used specific unless
# explicitly forced otherwise. We can just use that.
if os.name == 'nt':
return tmpdir
if not hasattr(os, 'getuid'):
_unsafe_dir()
dirname = '_jinja2-cache-%d' % os.getuid()
actual_dir = os.path.join(tmpdir, dirname)
try:
os.mkdir(actual_dir, stat.S_IRWXU)
except OSError as e:
if e.errno != errno.EEXIST:
raise
try:
os.chmod(actual_dir, stat.S_IRWXU)
actual_dir_stat = os.lstat(actual_dir)
if actual_dir_stat.st_uid != os.getuid() \
or not stat.S_ISDIR(actual_dir_stat.st_mode) \
or stat.S_IMODE(actual_dir_stat.st_mode) != stat.S_IRWXU:
_unsafe_dir()
except OSError as e:
if e.errno != errno.EEXIST:
raise
actual_dir_stat = os.lstat(actual_dir)
if actual_dir_stat.st_uid != os.getuid() \
or not stat.S_ISDIR(actual_dir_stat.st_mode) \
or stat.S_IMODE(actual_dir_stat.st_mode) != stat.S_IRWXU:
_unsafe_dir()
return actual_dir
def rmtree(path, ignore_errors=False, onerror=auto_chmod):
"""Recursively delete a directory tree.
This code is taken from the Python 2.4 version of 'shutil', because
the 2.3 version doesn't really work right.
"""
if ignore_errors:
def onerror(*args):
pass
elif onerror is None:
def onerror(*args):
raise
names = []
try:
names = os.listdir(path)
except os.error:
onerror(os.listdir, path, sys.exc_info())
for name in names:
fullname = os.path.join(path, name)
try:
mode = os.lstat(fullname).st_mode
except os.error:
mode = 0
if stat.S_ISDIR(mode):
rmtree(fullname, ignore_errors, onerror)
else:
try:
os.remove(fullname)
except os.error:
onerror(os.remove, fullname, sys.exc_info())
try:
os.rmdir(path)
except os.error:
onerror(os.rmdir, path, sys.exc_info())
