def _win32_is_junction(path):
"""
Determines if a path is a win32 junction
CommandLine:
python -m ubelt._win32_links _win32_is_junction
Example:
>>> # xdoc: +REQUIRES(WIN32)
>>> import ubelt as ub
>>> root = ub.ensure_app_cache_dir('ubelt', 'win32_junction')
>>> ub.delete(root)
>>> ub.ensuredir(root)
>>> dpath = join(root, 'dpath')
>>> djunc = join(root, 'djunc')
>>> ub.ensuredir(dpath)
>>> _win32_junction(dpath, djunc)
>>> assert _win32_is_junction(djunc) is True
>>> assert _win32_is_junction(dpath) is False
>>> assert _win32_is_junction('notafile') is False
"""
if not exists(path):
if os.path.isdir(path):
if not os.path.islink(path):
return True
return False
return jwfs.is_reparse_point(path) and not os.path.islink(path)
def _win32_read_junction(path):
"""
Returns the location that the junction points, raises ValueError if path is
not a junction.
Example:
>>> # xdoc: +REQUIRES(WIN32)
>>> import ubelt as ub
>>> root = ub.ensure_app_cache_dir('ubelt', 'win32_junction')
>>> ub.delete(root)
>>> ub.ensuredir(root)
>>> dpath = join(root, 'dpath')
>>> djunc = join(root, 'djunc')
>>> ub.ensuredir(dpath)
>>> _win32_junction(dpath, djunc)
>>> path = djunc
>>> pointed = _win32_read_junction(path)
>>> print('pointed = {!r}'.format(pointed))
"""
if not jwfs.is_reparse_point(path):
raise ValueError('not a junction')
# new version using the windows api
handle = jwfs.api.CreateFile(
path, 0, 0, None, jwfs.api.OPEN_EXISTING,
jwfs.api.FILE_FLAG_OPEN_REPARSE_POINT
| jwfs.api.FILE_FLAG_BACKUP_SEMANTICS, None)
if handle == jwfs.api.INVALID_HANDLE_VALUE:
raise WindowsError()
res = jwfs.reparse.DeviceIoControl(handle,
jwfs.api.FSCTL_GET_REPARSE_POINT, None,
10240)
bytes = jwfs.create_string_buffer(res)
p_rdb = jwfs.cast(bytes, jwfs.POINTER(jwfs.api.REPARSE_DATA_BUFFER))
rdb = p_rdb.contents
if rdb.tag not in [2684354563, jwfs.api.IO_REPARSE_TAG_SYMLINK]:
raise RuntimeError("Expected <2684354563 or 2684354572>, but got %d" %
rdb.tag)
jwfs.handle_nonzero_success(jwfs.api.CloseHandle(handle))
subname = rdb.get_substitute_name()
# probably has something to do with long paths, not sure
if subname.startswith('?\\'):
subname = subname[2:]
return subname
