Re: coreutils/man/rm.x - fails to mention POSIX "Refuse to remove path/. and path/.., as well as `.' and `..'

[Pádraig Brady]

On 23/09/2023 18:22, James Feeney via GNU coreutils General Discussion wrote:
> coreutils 9.3
> coreutils/man/rm.x
>
> Even though "rm" was modified,
> ====
> Sat Apr 20 00:03:09 1991  David J. MacKenzie  (djm at geech.gnu.ai.mit.edu)
> ...
> * rm.c (rm): Refuse to remove path/. and path/.., as well as `.' and `..', for 
> POSIX.
> ...
> ====
> the rm(1) man page completely fails to mention this particular POSIX promise.
>
> If the user already knows how GNU rm will respond to "rm -rf *", they don't 
> need to look at the man page.
>
> If the user does *not* know how GNU rm will respond to "rm -rf *", the GNU rm 
> man page is not going to help them.
>
> Language should be added to the GNU rm man page explicitly stating the POSIX 
> behavior:
> ====
> If either of the files dot or dot-dot are specified as the basename portion of 
> an operand (that is, the final pathname component) or if an operand resolves to 
> the root directory, rm shall write a diagnostic message to standard error and 
> do nothing more with such operands.
> ====
> including the additional requirement with respect to the root directory.

This is already mentioned in the info docs referenced from the man page. i.e.:
https://www.gnu.org/software/coreutils/rm

But I agree the man page should mention it.
I'd simplify the text though, and not mention anything about '/'
as that's more of an edge case, and already described
with the --preserve-root option.

I'll add the following to the man page:

 "Any attempt to remove a file whose last file name component is '.' or '..'
  is rejected with a diagnostic."

cheers,
Pádraig