On Sun 27 Feb 2022 at 05:35:25 (+0000), Alasdair McAndrew wrote: > Many thanks - your thought about write access was right on the money. For > reasons I can't determine, the folder in which I'm working had user write > access removed, so its permissions were dr-xr-xr-x instead of drwxr-xr-x as > they should have been. I don't know how I removed the write access, but > indeed I did; it's now been re-instated and all works well (phew).
Various gotchas exist. A frequent one is unpacking an archive, particularly as root, thereby copying the permissions embedded within the archive, including that for the top-level directory. Cheers, David.