# -*- coding: utf-8 -*-
"""The operating system file entry implementation."""
import os
import platform
import stat
import pysmdev
try:
import xattr
except ImportError:
xattr = None
from dfdatetime import posix_time as dfdatetime_posix_time
from dfvfs.lib import definitions
from dfvfs.path import os_path_spec
from dfvfs.vfs import attribute
from dfvfs.vfs import file_entry
from dfvfs.vfs import os_attribute
from dfvfs.vfs import os_directory
[docs]
class OSFileEntry(file_entry.FileEntry):
"""File system file entry that uses os."""
TYPE_INDICATOR = definitions.TYPE_INDICATOR_OS
_OS_IS_WINDOWS = platform.system() == 'Windows'
[docs]
def __init__(self, resolver_context, file_system, path_spec, is_root=False):
"""Initializes a file entry.
Args:
resolver_context (Context): resolver context.
file_system (FileSystem): file system.
path_spec (PathSpec): path specification.
is_root (Optional[bool]): True if the file entry is the root file entry
of the corresponding file system.
"""
location = getattr(path_spec, 'location', None)
# Windows does not support running os.stat on device files so we use
# libsmdev to do an initial check.
is_windows_device = False
if self._OS_IS_WINDOWS and location:
try:
# pylint: disable=no-member
is_windows_device = pysmdev.check_device(location)
except IOError:
pass
stat_info = None
if not is_windows_device and location:
# We are only catching OSError. However on the Windows platform
# a WindowsError can be raised as well. We are not catching that since
# that error does not exist on non-Windows platforms.
try:
stat_info = os.lstat(location)
except (IOError, OSError):
stat_info = None
super(OSFileEntry, self).__init__(
resolver_context, file_system, path_spec, is_root=is_root,
is_virtual=False)
self._is_windows_device = is_windows_device
self._location = location
self._name = None
self._stat_info = stat_info
if is_windows_device:
self.entry_type = definitions.FILE_ENTRY_TYPE_DEVICE
elif stat_info:
# If location contains a trailing segment separator and points to
# a symbolic link to a directory stat info will not indicate
# the file entry as a symbolic link. The following check ensures
# that the LINK type is correctly detected.
is_link = os.path.islink(location)
# The stat info member st_mode can have multiple types e.g.
# LINK and DIRECTORY in case of a symbolic link to a directory
# dfVFS currently only supports one type so we need to check
# for LINK first.
if stat.S_ISLNK(stat_info.st_mode) or is_link:
self.entry_type = definitions.FILE_ENTRY_TYPE_LINK
elif stat.S_ISREG(stat_info.st_mode):
self.entry_type = definitions.FILE_ENTRY_TYPE_FILE
elif stat.S_ISDIR(stat_info.st_mode):
self.entry_type = definitions.FILE_ENTRY_TYPE_DIRECTORY
elif stat.S_ISCHR(stat_info.st_mode):
self.entry_type = definitions.FILE_ENTRY_TYPE_CHARACTER_DEVICE
elif stat.S_ISBLK(stat_info.st_mode):
self.entry_type = definitions.FILE_ENTRY_TYPE_BLOCK_DEVICE
elif stat.S_ISFIFO(stat_info.st_mode):
self.entry_type = definitions.FILE_ENTRY_TYPE_PIPE
elif stat.S_ISSOCK(stat_info.st_mode):
self.entry_type = definitions.FILE_ENTRY_TYPE_SOCKET
def _GetAttributes(self):
"""Retrieves the attributes.
Returns:
list[Attribute]: attributes.
"""
if self._attributes is None:
self._attributes = []
if xattr:
try:
attribute_names = list(xattr.listxattr(self._location))
except IOError:
attribute_names = []
for name in attribute_names:
if isinstance(name, bytes):
name = os.fsdecode(name)
try:
extended_attribute = os_attribute.OSExtendedAttribute(
self._location, name)
self._attributes.append(extended_attribute)
except IOError:
pass
return self._attributes
def _GetDirectory(self):
"""Retrieves a directory.
Returns:
OSDirectory: a directory.
"""
if self.entry_type != definitions.FILE_ENTRY_TYPE_DIRECTORY:
return None
return os_directory.OSDirectory(self._file_system, self.path_spec)
def _GetLink(self):
"""Retrieves the link.
Returns:
str: full path of the linked file entry.
"""
if self._link is None:
self._link = ''
if self._location is None:
return self._link
self._link = os.readlink(self._location)
self._link = os.path.abspath(self._link)
return self._link
def _GetStatAttribute(self):
"""Retrieves a stat attribute.
Returns:
StatAttribute: a stat attribute or None if not available.
"""
stat_attribute = attribute.StatAttribute()
if not self._is_windows_device and self._stat_info:
stat_attribute.group_identifier = self._stat_info.st_gid
stat_attribute.inode_number = self._stat_info.st_ino
stat_attribute.mode = stat.S_IMODE(self._stat_info.st_mode)
stat_attribute.number_of_links = self._stat_info.st_nlink
stat_attribute.owner_identifier = self._stat_info.st_uid
stat_attribute.size = self._stat_info.st_size
stat_attribute.type = self.entry_type
return stat_attribute
def _GetSubFileEntries(self):
"""Retrieves sub file entries.
Yields:
OSFileEntry: a sub file entry.
"""
if self._directory is None:
self._directory = self._GetDirectory()
if self._directory:
for path_spec in self._directory.entries:
yield OSFileEntry(self._resolver_context, self._file_system, path_spec)
@property
def access_time(self):
"""dfdatetime.DateTimeValues: access time or None if not available."""
if self._stat_info is None:
return None
timestamp = getattr(self._stat_info, 'st_atime_ns', None)
if timestamp is not None:
return dfdatetime_posix_time.PosixTimeInNanoseconds(timestamp=timestamp)
timestamp = int(self._stat_info.st_atime)
return dfdatetime_posix_time.PosixTime(timestamp=timestamp)
@property
def change_time(self):
"""dfdatetime.DateTimeValues: change time or None if not available."""
if self._stat_info is None:
return None
# Per Python os.stat() documentation the value of stat_results.st_ctime
# contains the creation time on Windows.
if self._OS_IS_WINDOWS:
return None
timestamp = getattr(self._stat_info, 'st_ctime_ns', None)
if timestamp is not None:
return dfdatetime_posix_time.PosixTimeInNanoseconds(timestamp=timestamp)
timestamp = int(self._stat_info.st_ctime)
return dfdatetime_posix_time.PosixTime(timestamp=timestamp)
@property
def creation_time(self):
"""dfdatetime.DateTimeValues: creation time or None if not available."""
if self._stat_info is None:
return None
# Per Python os.stat() documentation the value of stat_results.st_ctime
# contains the creation time on Windows.
if self._OS_IS_WINDOWS:
timestamp = getattr(self._stat_info, 'st_ctime_ns', None)
if timestamp is not None:
return dfdatetime_posix_time.PosixTimeInNanoseconds(timestamp=timestamp)
timestamp = int(self._stat_info.st_ctime)
else:
timestamp = getattr(self._stat_info, 'st_birthtime', None)
if timestamp is None:
return None
return dfdatetime_posix_time.PosixTime(timestamp=timestamp)
@property
def modification_time(self):
"""dfdatetime.DateTimeValues: modification time or None if not available."""
if self._stat_info is None:
return None
timestamp = getattr(self._stat_info, 'st_mtime_ns', None)
if timestamp is not None:
return dfdatetime_posix_time.PosixTimeInNanoseconds(timestamp=timestamp)
timestamp = int(self._stat_info.st_mtime)
return dfdatetime_posix_time.PosixTime(timestamp=timestamp)
@property
def name(self):
"""str: name of the file entry, without the full path."""
if self._name is None:
if self._location is not None:
self._name = self._file_system.BasenamePath(self._location)
return self._name
@property
def size(self):
"""int: size of the file entry in bytes or None if not available."""
if self._is_windows_device or not self._stat_info:
return None
return self._stat_info.st_size
[docs]
def GetLinkedFileEntry(self):
"""Retrieves the linked file entry, for example for a symbolic link.
Returns:
OSFileEntry: linked file entry or None if not available.
"""
link = self._GetLink()
if not link:
return None
path_spec = os_path_spec.OSPathSpec(location=link)
return OSFileEntry(self._resolver_context, self._file_system, path_spec)
[docs]
def GetParentFileEntry(self):
"""Retrieves the parent file entry.
Returns:
OSFileEntry: parent file entry or None if not available.
"""
if self._location is None:
return None
parent_location = self._file_system.DirnamePath(self._location)
if parent_location is None:
return None
if parent_location == '':
parent_location = self._file_system.PATH_SEPARATOR
path_spec = os_path_spec.OSPathSpec(location=parent_location)
return OSFileEntry(self._resolver_context, self._file_system, path_spec)