bug#29069: bug#31043: [PATCH] changed presentation in 'File permissions' in 'numeric, modes'

[Paul Eggert]

On 04/03/2018 12:29 PM, kalle wrote:
> But what do you think of my teaching concept, to try to explain why a
> `7' in `755' means =4+2+1=111=rwx="rwx for owner", which is assumed as
> self-evident or intuitive in both the original text and your patch?

I think it's out of place in the coreutils manual, just as (for example) 
the manual need not mention computer keyboard layouts in order to tell 
users how to type 'sort -r'. Assuming basic computer concepts simplifies 
the manual and makes it easier for typical users to read, which is a win.

>                 
> where would be a place, to formulate the problem `7=4+2+1'
> more generally?

One place would be:

https://en.wikipedia.org/wiki/Octal


> Why didn't you take over my correction from "are sometimes special" to
> "have a special meaning for directories" ?

I didn't think that was necessary, since the parenthesized 
cross-reference already mentioned "Directory". The main point here is 
that the leading "0" is not necessary, not that excess leading "0"s 
sometimes have special meanings.