getxattr position parameter unclear

[ThomasWaldmann]

From the code:

    def getxattr(self, path: str, name: str, position=0) -> bytes:
        '''
        Return the extended file attribute value to the specified (key) name and path.
        Should return a bytes object.
        '''
        # I have no idea what 'position' does. It is a compatibility placeholder specifically for
        # "if _system in ('Darwin', 'Darwin-MacFuse', 'FreeBSD'):", for which getxattr_t supposedly has
        # an additional uint32_t argument for some reason. I think that including FreeBSD here might be a bug,
        # because it also only uses libfuse. TODO: Somehow need to test this!
        # MacFuse does indeed have that extra argument but also only in some overload, not in "Vanilla":
        # https://github.com/macfuse/library/blob/6c26f28394c1cbda2428498c03e1f898c775404e/include/fuse.h#L1465-L1471
        # It seems to be some kind of position, maybe to query very long values in a chunked manner with an offset?
        raise FuseOSError(ENOTSUP)

[ThomasWaldmann]

Hmm, running tests using os.getxattr does not work on macOS, because the macOS python lacks these functions.

Likely the same on FreeBSD, the python docs say "These functions are all available on Linux only.". Furthermore, the os.getxattr api does not have a position parameter.

https://docs.python.org/3/library/os.html#linux-extended-attributes

So guess we can not test this unless we add an xattr lib as a new test dependency.

[ThomasWaldmann]

About the position parameter, see what pdnc (2 comments) says there:

https://www.jwz.org/blog/2025/12/xattr/#comment-264255

[ThomasWaldmann]

Hmm, it gets worse: NONE of the available python xattr libs supports that position parameter.

So we can't easily test that.

Just ignore that it exists?

[mxmlnkn]

Just ignore that it exists?

Would be fine with me.