"""
.. codeauthor:: Tsuyoshi Hombashi <tsuyoshi.hombashi@gmail.com>
"""
import itertools
import ntpath
import posixpath
import re
import warnings
from pathlib import Path, PurePath
from typing import Optional, Pattern, Sequence, Tuple
from ._base import AbstractSanitizer, AbstractValidator, BaseFile, BaseValidator
from ._common import findall_to_str, to_str, validate_pathtype
from ._const import DEFAULT_MIN_LEN, INVALID_CHAR_ERR_MSG_TMPL, Platform
from ._types import PathType, PlatformType
from .error import ErrorAttrKey, ErrorReason, InvalidCharError, ValidationError
from .handler import ReservedNameHandler, ValidationErrorHandler
_DEFAULT_MAX_FILENAME_LEN = 255
_RE_INVALID_FILENAME = re.compile(f"[{re.escape(BaseFile._INVALID_FILENAME_CHARS):s}]", re.UNICODE)
_RE_INVALID_WIN_FILENAME = re.compile(
f"[{re.escape(BaseFile._INVALID_WIN_FILENAME_CHARS):s}]", re.UNICODE
)
class FileNameSanitizer(AbstractSanitizer):
def __init__(
self,
max_len: int = _DEFAULT_MAX_FILENAME_LEN,
fs_encoding: Optional[str] = None,
platform: Optional[PlatformType] = None,
null_value_handler: Optional[ValidationErrorHandler] = None,
reserved_name_handler: Optional[ValidationErrorHandler] = None,
additional_reserved_names: Optional[Sequence[str]] = None,
validate_after_sanitize: bool = False,
validator: Optional[AbstractValidator] = None,
) -> None:
if validator:
fname_validator = validator
else:
fname_validator = FileNameValidator(
min_len=DEFAULT_MIN_LEN,
max_len=max_len,
fs_encoding=fs_encoding,
check_reserved=True,
additional_reserved_names=additional_reserved_names,
platform=platform,
)
super().__init__(
max_len=max_len,
fs_encoding=fs_encoding,
null_value_handler=null_value_handler,
reserved_name_handler=reserved_name_handler,
additional_reserved_names=additional_reserved_names,
platform_max_len=_DEFAULT_MAX_FILENAME_LEN,
platform=platform,
validate_after_sanitize=validate_after_sanitize,
validator=fname_validator,
)
self._sanitize_regexp = self._get_sanitize_regexp()
def sanitize(self, value: PathType, replacement_text: str = "") -> PathType:
try:
validate_pathtype(value, allow_whitespaces=not self._is_windows(include_universal=True))
except ValidationError as e:
if e.reason == ErrorReason.NULL_NAME:
if isinstance(value, PurePath):
raise
return self._null_value_handler(e)
raise
sanitized_filename = self._sanitize_regexp.sub(replacement_text, str(value))
sanitized_filename = sanitized_filename[: self.max_len]
try:
self._validator.validate(sanitized_filename)
except ValidationError as e:
if e.reason == ErrorReason.RESERVED_NAME:
replacement_word = self._reserved_name_handler(e)
if e.reserved_name != replacement_word:
sanitized_filename = re.sub(
re.escape(e.reserved_name), replacement_word, sanitized_filename
)
elif e.reason == ErrorReason.INVALID_CHARACTER and self._is_windows(
include_universal=True
):
# Do not start a file or directory name with a space
sanitized_filename = sanitized_filename.lstrip(" ")
# Do not end a file or directory name with a space or a period
sanitized_filename = sanitized_filename.rstrip(" ")
if sanitized_filename not in (".", ".."):
sanitized_filename = sanitized_filename.rstrip(" .")
elif e.reason == ErrorReason.NULL_NAME:
sanitized_filename = self._null_value_handler(e)
if self._validate_after_sanitize:
try:
self._validator.validate(sanitized_filename)
except ValidationError as e:
raise ValidationError(
description=str(e),
reason=ErrorReason.INVALID_AFTER_SANITIZE,
platform=self.platform,
)
if isinstance(value, PurePath):
return Path(sanitized_filename)
return sanitized_filename
def _get_sanitize_regexp(self) -> Pattern[str]:
if self._is_windows(include_universal=True):
return _RE_INVALID_WIN_FILENAME
return _RE_INVALID_FILENAME
class FileNameValidator(BaseValidator):
_WINDOWS_RESERVED_FILE_NAMES = ("CON", "PRN", "AUX", "CLOCK$", "NUL") + tuple(
f"{name:s}{num:d}" for name, num in itertools.product(("COM", "LPT"), range(1, 10))
)
_MACOS_RESERVED_FILE_NAMES = (":",)
@property
def reserved_keywords(self) -> Tuple[str, ...]:
common_keywords = super().reserved_keywords
if self._is_universal():
word_set = set(
common_keywords
+ self._WINDOWS_RESERVED_FILE_NAMES
+ self._MACOS_RESERVED_FILE_NAMES
)
elif self._is_windows():
word_set = set(common_keywords + self._WINDOWS_RESERVED_FILE_NAMES)
elif self._is_posix() or self._is_macos():
word_set = set(common_keywords + self._MACOS_RESERVED_FILE_NAMES)
else:
word_set = set(common_keywords)
return tuple(sorted(word_set))
def __init__(
self,
min_len: int = DEFAULT_MIN_LEN,
max_len: int = _DEFAULT_MAX_FILENAME_LEN,
fs_encoding: Optional[str] = None,
platform: Optional[PlatformType] = None,
check_reserved: bool = True,
additional_reserved_names: Optional[Sequence[str]] = None,
) -> None:
super().__init__(
min_len=min_len,
max_len=max_len,
fs_encoding=fs_encoding,
check_reserved=check_reserved,
additional_reserved_names=additional_reserved_names,
platform_max_len=_DEFAULT_MAX_FILENAME_LEN,
platform=platform,
)
def validate(self, value: PathType) -> None:
validate_pathtype(value, allow_whitespaces=not self._is_windows(include_universal=True))
unicode_filename = to_str(value)
byte_ct = len(unicode_filename.encode(self._fs_encoding))
self.validate_abspath(unicode_filename)
err_kwargs = {
ErrorAttrKey.REASON: ErrorReason.INVALID_LENGTH,
ErrorAttrKey.PLATFORM: self.platform,
ErrorAttrKey.FS_ENCODING: self._fs_encoding,
ErrorAttrKey.BYTE_COUNT: byte_ct,
}
if byte_ct > self.max_len:
raise ValidationError(
[
f"filename is too long: expected<={self.max_len:d} bytes, actual={byte_ct:d} bytes"
],
**err_kwargs,
)
if byte_ct < self.min_len:
raise ValidationError(
[
f"filename is too short: expected>={self.min_len:d} bytes, actual={byte_ct:d} bytes"
],
**err_kwargs,
)
self._validate_reserved_keywords(unicode_filename)
self.__validate_universal_filename(unicode_filename)
if self._is_windows(include_universal=True):
self.__validate_win_filename(unicode_filename)
def validate_abspath(self, value: str) -> None:
err = ValidationError(
description=f"found an absolute path ({value}), expected a filename",
platform=self.platform,
reason=ErrorReason.FOUND_ABS_PATH,
)
if self._is_windows(include_universal=True):
if ntpath.isabs(value):
raise err
if posixpath.isabs(value):
raise err
def __validate_universal_filename(self, unicode_filename: str) -> None:
match = _RE_INVALID_FILENAME.findall(unicode_filename)
if match:
raise InvalidCharError(
INVALID_CHAR_ERR_MSG_TMPL.format(
invalid=findall_to_str(match), value=repr(unicode_filename)
),
platform=Platform.UNIVERSAL,
)
def __validate_win_filename(self, unicode_filename: str) -> None:
match = _RE_INVALID_WIN_FILENAME.findall(unicode_filename)
if match:
raise InvalidCharError(
INVALID_CHAR_ERR_MSG_TMPL.format(
invalid=findall_to_str(match), value=repr(unicode_filename)
),
platform=Platform.WINDOWS,
)
if unicode_filename in (".", ".."):
return
KB2829981_err_tmpl = "{}. Refer: https://learn.microsoft.com/en-us/troubleshoot/windows-client/shell-experience/file-folder-name-whitespace-characters" # noqa: E501
if unicode_filename[-1] in (" ", "."):
raise InvalidCharError(
INVALID_CHAR_ERR_MSG_TMPL.format(
invalid=re.escape(unicode_filename[-1]), value=repr(unicode_filename)
),
platform=Platform.WINDOWS,
description=KB2829981_err_tmpl.format(
"Do not end a file or directory name with a space or a period"
),
)
if unicode_filename[0] in (" "):
raise InvalidCharError(
INVALID_CHAR_ERR_MSG_TMPL.format(
invalid=re.escape(unicode_filename[0]), value=repr(unicode_filename)
),
platform=Platform.WINDOWS,
description=KB2829981_err_tmpl.format(
"Do not start a file or directory name with a space"
),
)
[docs]
def validate_filename(
filename: PathType,
platform: Optional[PlatformType] = None,
min_len: int = DEFAULT_MIN_LEN,
max_len: int = _DEFAULT_MAX_FILENAME_LEN,
fs_encoding: Optional[str] = None,
check_reserved: bool = True,
additional_reserved_names: Optional[Sequence[str]] = None,
) -> None:
"""Verifying whether the ``filename`` is a valid file name or not.
Args:
filename:
Filename to validate.
platform:
Target platform name of the filename.
.. include:: platform.txt
min_len:
Minimum byte length of the ``filename``. The value must be greater or equal to one.
Defaults to ``1``.
max_len:
Maximum byte length of the ``filename``. The value must be lower than:
- ``Linux``: 4096
- ``macOS``: 1024
- ``Windows``: 260
- ``universal``: 260
Defaults to ``255``.
fs_encoding:
Filesystem encoding that used to calculate the byte length of the filename.
If |None|, get the value from the execution environment.
check_reserved:
If |True|, check reserved names of the ``platform``.
additional_reserved_names:
Additional reserved names to check.
Case insensitive.
Raises:
ValidationError (ErrorReason.INVALID_LENGTH):
If the ``filename`` is longer than ``max_len`` characters.
ValidationError (ErrorReason.INVALID_CHARACTER):
If the ``filename`` includes invalid character(s) for a filename:
|invalid_filename_chars|.
The following characters are also invalid for Windows platforms:
|invalid_win_filename_chars|.
ValidationError (ErrorReason.RESERVED_NAME):
If the ``filename`` equals reserved name by OS.
Windows reserved name is as follows:
``"CON"``, ``"PRN"``, ``"AUX"``, ``"NUL"``, ``"COM[1-9]"``, ``"LPT[1-9]"``.
Example:
:ref:`example-validate-filename`
See Also:
`Naming Files, Paths, and Namespaces - Win32 apps | Microsoft Docs
<https://docs.microsoft.com/en-us/windows/win32/fileio/naming-a-file>`__
"""
FileNameValidator(
platform=platform,
min_len=min_len,
max_len=max_len,
fs_encoding=fs_encoding,
check_reserved=check_reserved,
additional_reserved_names=additional_reserved_names,
).validate(filename)
[docs]
def is_valid_filename(
filename: PathType,
platform: Optional[PlatformType] = None,
min_len: int = DEFAULT_MIN_LEN,
max_len: Optional[int] = None,
fs_encoding: Optional[str] = None,
check_reserved: bool = True,
additional_reserved_names: Optional[Sequence[str]] = None,
) -> bool:
"""Check whether the ``filename`` is a valid name or not.
Args:
filename:
A filename to be checked.
platform:
Target platform name of the filename.
Example:
:ref:`example-is-valid-filename`
See Also:
:py:func:`.validate_filename()`
"""
return FileNameValidator(
platform=platform,
min_len=min_len,
max_len=-1 if max_len is None else max_len,
fs_encoding=fs_encoding,
check_reserved=check_reserved,
additional_reserved_names=additional_reserved_names,
).is_valid(filename)
[docs]
def sanitize_filename(
filename: PathType,
replacement_text: str = "",
platform: Optional[PlatformType] = None,
max_len: Optional[int] = _DEFAULT_MAX_FILENAME_LEN,
fs_encoding: Optional[str] = None,
check_reserved: Optional[bool] = None,
null_value_handler: Optional[ValidationErrorHandler] = None,
reserved_name_handler: Optional[ValidationErrorHandler] = None,
additional_reserved_names: Optional[Sequence[str]] = None,
validate_after_sanitize: bool = False,
) -> PathType:
"""Make a valid filename from a string.
To make a valid filename, the function does the following:
- Replace invalid characters as file names included in the ``filename``
with the ``replacement_text``. Invalid characters are:
- unprintable characters
- |invalid_filename_chars|
- for Windows (or universal) only: |invalid_win_filename_chars|
- Replace a value if a sanitized value is a reserved name by operating systems
with a specified handler by ``reserved_name_handler``.
Args:
filename: Filename to sanitize.
replacement_text:
Replacement text for invalid characters. Defaults to ``""``.
platform:
Target platform name of the filename.
.. include:: platform.txt
max_len:
Maximum byte length of the ``filename``.
Truncate the name length if the ``filename`` length exceeds this value.
Defaults to ``255``.
fs_encoding:
Filesystem encoding that used to calculate the byte length of the filename.
If |None|, get the value from the execution environment.
check_reserved:
[Deprecated] Use 'reserved_name_handler' instead.
null_value_handler:
Function called when a value after sanitization is an empty string.
You can specify predefined handlers:
- :py:func:`~.handler.NullValueHandler.return_null_string`
- :py:func:`~.handler.NullValueHandler.return_timestamp`
- :py:func:`~.handler.raise_error`
Defaults to :py:func:`.handler.NullValueHandler.return_null_string` that just return ``""``.
reserved_name_handler:
Function called when a value after sanitization is a reserved name.
You can specify predefined handlers:
- :py:meth:`~.handler.ReservedNameHandler.add_leading_underscore`
- :py:meth:`~.handler.ReservedNameHandler.add_trailing_underscore`
- :py:meth:`~.handler.ReservedNameHandler.as_is`
- :py:func:`~.handler.raise_error`
Defaults to :py:func:`.handler.add_trailing_underscore`.
additional_reserved_names:
Additional reserved names to sanitize.
Case insensitive.
validate_after_sanitize:
Execute validation after sanitization to the file name.
Returns:
Same type as the ``filename`` (str or PathLike object):
Sanitized filename.
Raises:
ValueError:
If the ``filename`` is an invalid filename.
Example:
:ref:`example-sanitize-filename`
"""
if check_reserved is not None:
warnings.warn(
"'check_reserved' is deprecated. Use 'reserved_name_handler' instead.",
DeprecationWarning,
)
if check_reserved is False:
reserved_name_handler = ReservedNameHandler.as_is
return FileNameSanitizer(
platform=platform,
max_len=-1 if max_len is None else max_len,
fs_encoding=fs_encoding,
null_value_handler=null_value_handler,
reserved_name_handler=reserved_name_handler,
additional_reserved_names=additional_reserved_names,
validate_after_sanitize=validate_after_sanitize,
).sanitize(filename, replacement_text)