Hotel/env/lib/python3.5/site-packages/django/utils/_os.py

69 lines
2.4 KiB
Python

import os
import tempfile
from os.path import abspath, dirname, join, normcase, sep
from django.core.exceptions import SuspiciousFileOperation
from django.utils.encoding import force_text
# For backwards-compatibility in Django 2.0
abspathu = abspath
def upath(path):
"""Always return a unicode path (did something for Python 2)."""
return path
def npath(path):
"""
Always return a native path, that is unicode on Python 3 and bytestring on
Python 2. Noop for Python 3.
"""
return path
def safe_join(base, *paths):
"""
Join one or more path components to the base path component intelligently.
Return a normalized, absolute version of the final path.
Raise ValueError if the final path isn't located inside of the base path
component.
"""
base = force_text(base)
paths = [force_text(p) for p in paths]
final_path = abspath(join(base, *paths))
base_path = abspath(base)
# Ensure final_path starts with base_path (using normcase to ensure we
# don't false-negative on case insensitive operating systems like Windows),
# further, one of the following conditions must be true:
# a) The next character is the path separator (to prevent conditions like
# safe_join("/dir", "/../d"))
# b) The final path must be the same as the base path.
# c) The base path must be the most root path (meaning either "/" or "C:\\")
if (not normcase(final_path).startswith(normcase(base_path + sep)) and
normcase(final_path) != normcase(base_path) and
dirname(normcase(base_path)) != normcase(base_path)):
raise SuspiciousFileOperation(
'The joined path ({}) is located outside of the base path '
'component ({})'.format(final_path, base_path))
return final_path
def symlinks_supported():
"""
Return whether or not creating symlinks are supported in the host platform
and/or if they are allowed to be created (e.g. on Windows it requires admin
permissions).
"""
with tempfile.TemporaryDirectory() as temp_dir:
original_path = os.path.join(temp_dir, 'original')
symlink_path = os.path.join(temp_dir, 'symlink')
os.makedirs(original_path)
try:
os.symlink(original_path, symlink_path)
supported = True
except (OSError, NotImplementedError):
supported = False
return supported