ls: --group-directories=first/last

[pstef]

Summary

Implement --group-directories-first for compatibility with GNU ls.

Also implement --group-directories which takes a parameter.
"first" is equivalent to --group-directories-first, "last" gives
reversed sorting.

Changes in sorting between elements of the same type (files,
directories) are not intended.

[ziaee]

I do not like long options. We have a different culture and tradition that has a steep learning curve, but has led to the last living usable, daily driveable CLI. Long options are great for scripts but ruin the usability of CLI as a UX. This is just a comment and not a request for changes or nack. Cc'ing community leaders for review, and manpages since this is a manpage change.

[pstef]

This is for compatibility with GNU ls, where this is an equally long option.
We already distribute a system where ls is an alias.

[jhb]

Supporting the GNU ls option (--group-directories-first) as a long option seems fine to me. For the FreeBSD-specific extension the similar long option is probably ok. If -G wasn't already claimed by color ls perhaps that would have been a good candidate, but there are very few remaining single-letter options.

bin/ls/ls.1

315 ↗

(On Diff #148896)

Does this need a note about not being compatible with POSIX? I note that --color is missing such a note but other single-letter extensions are annotated as such both in the option description and in the STANDARDS section.

[pstef]

bin/ls/ls.1

315 ↗

(On Diff #148896)

I don't have a good idea how to craft the words here.

[pstef]

Try to address comments from jhb.