import os import stat import sys import tempfile from os.path import join, normcase, normpath, abspath, isabs, sep, dirname from django.utils.encoding import force_text from django.utils import six try: WindowsError = WindowsError except NameError: class WindowsError(Exception): pass if six.PY2: fs_encoding = sys.getfilesystemencoding() or sys.getdefaultencoding() # Under Python 2, define our own abspath function that can handle joining # unicode paths to a current working directory that has non-ASCII characters # in it. This isn't necessary on Windows since the Windows version of abspath # handles this correctly. It also handles drive letters differently than the # pure Python implementation, so it's best not to replace it. if six.PY3 or os.name == 'nt': abspathu = abspath else: def abspathu(path): """ Version of os.path.abspath that uses the unicode representation of the current working directory, thus avoiding a UnicodeDecodeError in join when the cwd has non-ASCII characters. """ if not isabs(path): path = join(os.getcwdu(), path) return normpath(path) def upath(path): """ Always return a unicode path. """ if six.PY2 and not isinstance(path, six.text_type): return path.decode(fs_encoding) return path def npath(path): """ Always return a native path, that is unicode on Python 3 and bytestring on Python 2. """ if six.PY2 and not isinstance(path, bytes): return path.encode(fs_encoding) return path def safe_join(base, *paths): """ Joins one or more path components to the base path component intelligently. Returns a normalized, absolute version of the final path. The final path must be located inside of the base path component (otherwise a ValueError is raised). """ base = force_text(base) paths = [force_text(p) for p in paths] final_path = abspathu(join(base, *paths)) base_path = abspathu(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 ValueError('The joined path (%s) is located outside of the base ' 'path component (%s)' % (final_path, base_path)) return final_path def rmtree_errorhandler(func, path, exc_info): """ On Windows, some files are read-only (e.g. in in .svn dirs), so when rmtree() tries to remove them, an exception is thrown. We catch that here, remove the read-only attribute, and hopefully continue without problems. """ exctype, value = exc_info[:2] # looking for a windows error if exctype is not WindowsError or 'Access is denied' not in str(value): raise # file type should currently be read only if ((os.stat(path).st_mode & stat.S_IREAD) != stat.S_IREAD): raise # convert to read/write os.chmod(path, stat.S_IWRITE) # use the original function to repeat the operation func(path) def symlinks_supported(): """ A function to check if 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). """ tmpdir = tempfile.mkdtemp() original_path = os.path.join(tmpdir, 'original') symlink_path = os.path.join(tmpdir, 'symlink') os.makedirs(original_path) try: os.symlink(original_path, symlink_path) supported = True except (OSError, NotImplementedError, AttributeError): supported = False else: os.remove(symlink_path) finally: os.rmdir(original_path) os.rmdir(tmpdir) return supported