commit fdd371ff4db49cd9456928fea87ebd6d70913a37
parent a4d07db7c9b9ccea857b548534341c1f0d6f3b65
Author: FIGBERT <figbertwelner@gmail.com>
Date: Sun, 14 Jul 2019 18:42:18 -0700
Adding filepath checker to Scripts/
Diffstat:
| A | Scripts/file_check.py | | | 107 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ |
1 file changed, 107 insertions(+), 0 deletions(-)
diff --git a/Scripts/file_check.py b/Scripts/file_check.py
@@ -0,0 +1,106 @@
+import errno, os, tempfile, sys
+
+#Windows-specific error code indicating an invalid pathname
+ERROR_INVALID_NAME = 123
+
+
+def is_pathname_valid(pathname: str) -> bool:
+ '''
+ Return `True` if the passed pathname is a valid pathname for the current
+ OS, and `False` otherwise. If the pathname provided is either not a string
+ or is a string but is empty, return `False`.
+ '''
+ try:
+ if not isinstance(pathname, str) or not pathname:
+ return False
+ #Strips this pathname's Windows-specific drive specifier (e.g., `C:\`)
+ #if any.
+ _, pathname = os.path.splitdrive(pathname)
+
+ # Directory guaranteed to exist. If the current OS is Windows, this is
+ # the drive to which Windows was installed (e.g., the "%HOMEDRIVE%"
+ # environment variable); else, the typical root directory.
+ root_dirname = os.environ.get('HOMEDRIVE', 'C:') \
+ if sys.platform == 'win32' else os.path.sep
+ assert os.path.isdir(root_dirname)
+
+ # Append a path separator to this directory if needed.
+ root_dirname = root_dirname.rstrip(os.path.sep) + os.path.sep
+
+ # Test whether each path component split from this pathname is valid or
+ # not, ignoring non-existent and non-readable path components.
+ for pathname_part in pathname.split(os.path.sep):
+ try:
+ os.lstat(root_dirname + pathname_part)
+ except OSError as exc:
+ if hasattr(exc, 'winerror'):
+ if exc.winerror == ERROR_INVALID_NAME:
+ return False
+ elif exc.errno in {errno.ENAMETOOLONG, errno.ERANGE}:
+ return False
+ except TypeError as exc:
+ return False
+ else:
+ return True
+
+
+def is_path_creatable(pathname: str) -> bool:
+ '''
+ Return `True` if the current user has sufficient permissions to create the
+ passed pathname; `False` otherwise.
+ '''
+ # Parent directory of the passed path. If empty, we substitute the current
+ # working directory (CWD) instead.
+ dirname = os.path.dirname(pathname) or os.getcwd()
+ return os.access(dirname, os.W_OK)
+
+
+def is_path_exists_or_creatable(pathname: str) -> bool:
+ '''
+ Return `True` if the passed pathname is a valid pathname for the current
+ OS and either currently exists or is hypothetically createable; `False
+ otherwise.
+ '''
+ try:
+ # To prevent "os" module calls from raising undesirable exceptions on
+ # invalid pathnames, is_pathname_valid() is explicitly called first.
+ return is_pathname_valid(pathname) and (
+ os.path.exists(pathname) or is_path_creatable(pathname))
+ except OSError:
+ return False
+
+
+def is_path_sibling_creatable(pathname: str) -> bool:
+ '''
+ Return `True` if the current user has sifficient permissions to create
+ siblings (arbitrary files in the parent directory) of the passed pathname,
+ and `False` otherwise.
+ '''
+ # Parent directory of the passed path. If empty, we substitute the current
+ # working directory (CWD) instead.
+ dirname = os.path.dirname(pathname) or os.getcwd()
+
+ try:
+ # Opening and immediately closing the temporary file
+ with tempfile.TemporaryFile(dir=dirname): pass
+ return True
+ # All exceptions fall under the EnvironmentError subclass
+ except EnvironmentError:
+ return False
+
+
+def is_path_exists_or_creatable_portable(pathname: str) -> bool:
+ '''
+ Return `True` if the passed pathname is a valid pathname on the current OS
+ and either currently exists or is hypothetically creatable in a
+ cross-platform manner optimized for POSIX-unfriendly filesystems; `False`
+ otherwise.
+ Never raises errors.
+ '''
+ try:
+ # Calls is_pathname_valid() first to prevent "os" module from raising
+ # undesirable exceptions on invalid pathnames
+ return is_pathname_valid(pathname) and (
+ os.path.exists(pathname) or is_path_sibling_creatable(pathname))
+ except OSError:
+ pass
+\ No newline at end of file
