I thought so too, but found this reference to a Version 1 mkdir:

https://man.cat-v.org/unix-1st/1/mkdir

I recall reading a Version 6 or 7 man page about mkfs that included the ability to populate a file system with some directories, and I thought that implied that users couldn't create directories. The man page referenced above hints that mkdir is run as the 'system user', presumably root, and becomes the owner of new directories.

Rik


On Tue, Apr 29, 2025 at 4:28 AM Jaap Akkerhuis <jaapna@xs4all.nl> wrote:
I seem to remember that V7 was the first suystem which had a mkdir system call. That might have changed what ls -a showed.

        jaap