[Feature request] Second level sort method (for --sort=extension)

[hasecilu]

• os: ArcoLinux
• lsd --version: lsd 0.23.1
• echo $TERM: xterm-256color
• echo $LS_COLORS: rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:mi=00:su=37;41:sg=30;43:ca=00:tw=30;42:ow=34;42:st=37;44:ex=01;32:.tar=01;31:.tgz=01;31:.arc=01;31:.arj=01;31:.taz=01;31:.lha=01;31:.lz4=01;31:.lzh=01;31:.lzma=01;31:.tlz=01;31:.txz=01;31:.tzo=01;31:.t7z=01;31:.zip=01;31:.z=01;31:.dz=01;31:.gz=01;31:.lrz=01;31:.lz=01;31:.lzo=01;31:.xz=01;31:.zst=01;31:.tzst=01;31:.bz2=01;31:.bz=01;31:.tbz=01;31:.tbz2=01;31:.tz=01;31:.deb=01;31:.rpm=01;31:.jar=01;31:.war=01;31:.ear=01;31:.sar=01;31:.rar=01;31:.alz=01;31:.ace=01;31:.zoo=01;31:.cpio=01;31:.7z=01;31:.rz=01;31:.cab=01;31:.wim=01;31:.swm=01;31:.dwm=01;31:.esd=01;31:.avif=01;35:.jpg=01;35:.jpeg=01;35:.mjpg=01;35:.mjpeg=01;35:.gif=01;35:.bmp=01;35:.pbm=01;35:.pgm=01;35:.ppm=01;35:.tga=01;35:.xbm=01;35:.xpm=01;35:.tif=01;35:.tiff=01;35:.png=01;35:.svg=01;35:.svgz=01;35:.mng=01;35:.pcx=01;35:.mov=01;35:.mpg=01;35:.mpeg=01;35:.m2v=01;35:.mkv=01;35:.webm=01;35:.webp=01;35:.ogm=01;35:.mp4=01;35:.m4v=01;35:.mp4v=01;35:.vob=01;35:.qt=01;35:.nuv=01;35:.wmv=01;35:.asf=01;35:.rm=01;35:.rmvb=01;35:.flc=01;35:.avi=01;35:.fli=01;35:.flv=01;35:.gl=01;35:.dl=01;35:.xcf=01;35:.xwd=01;35:.yuv=01;35:.cgm=01;35:.emf=01;35:.ogv=01;35:.ogx=01;35:.aac=00;36:.au=00;36:.flac=00;36:.m4a=00;36:.mid=00;36:.midi=00;36:.mka=00;36:.mp3=00;36:.mpc=00;36:.ogg=00;36:.ra=00;36:.wav=00;36:.oga=00;36:.opus=00;36:.spx=00;36:.xspf=00;36:~=00;90:#=00;90:.bak=00;90:.old=00;90:.orig=00;90:.part=00;90:.rej=00;90:.swp=00;90:.tmp=00;90:.dpkg-dist=00;90:.dpkg-old=00;90:.ucf-dist=00;90:.ucf-new=00;90:.ucf-old=00;90:.rpmnew=00;90:.rpmorig=00;90:.rpmsave=00;90:

Expected behavior

Be able to have a nested sort option over the main one. This will allow user to nest sorting methods (if applicable). Sort by name is absolute, there is no space for a "second level sorting method" Sort by extension groups files but don't seem to be an order in them (per group/section) by name nor time nor size.

A good option could be able to specify a second level sort method, in my case I prefer by name and if it's used with --sort=extension each "extension group" will sort its files alphabetically allowing the user to find faster specific file(s). Very useful with a long list of files. It's very common to find this setting in graphical file browsers.

Actual behavior

The default sort order is by name, files with same extension are separated.

$ lsd --icon never
2022-09-13 (2).png   Avanxe7.zip  ID_394_507.zip       p5000      venus_box_cover_mod.stl  VID_20220819_175931.mp4
20221204_121637.mp4  BPSK         image.png            Solid.png  vernier_caliper.FCStd    
asmdemo.c            Day7.c       oboi7.com-14695.png  TS80P.zip  VID_20211227_175134.mp4 

If the sort order is by extension, files with same extension are grouped but each group itself is not sorted by name.

$ lsd --icon never --sort=extension
BPSK                   Day7.c                   2022-09-13 (2).png   venus_box_cover_mod.stl
p5000                  VID_20211227_175134.mp4  oboi7.com-14695.png  ID_394_507.zip
vernier_caliper.FCStd  VID_20220819_175931.mp4  Solid.png            Avanxe7.zip
asmdemo.c              20221204_121637.mp4      image.png            TS80P.zip

Is better

$ lsd --icon never --sort=extension
BPSK                   vernier_caliper.FCStd       022-09-13 (2).png       venus_box_cover_mod.stl
p5000                  20221204_121637.mp4         image.png               Avanxe7.zip
asmdemo.c              VID_20211227_175134.mp4     oboi7.com-14695.png     ID_394_507.zip
Day7.c                 VID_20220819_175931.mp4     Solid.png               TS80P.zip

[hasecilu]

Things to note:

• Is case sensitive, extensions like FCStd, JPG, PDF are first than c, csv, h. I think is better to make it insensitive to capital letters.
• I realize that in GUI file browsers files are not grouped by extension but by type and each type is a group with several extensions associated (something like this), inside that group extensions are sorted alphabetically and again files with same extension are sorted by name.

[raabrp]

If you don't mind the inefficiency of running ls first, I'm currently using the following work-around to get the sorting that I prefer from ls with the display niceties of lsd (zsh shell on Fedora 38):

alias ll="ls -1X --sort=extension --group-directories-first --color=never | xargs lsd -Uld"

• The -1 flag to ls outputs one item per line.
• --color=never suppresses terminal escape sequences in the output, leaving pure file and directory names as outputs.
• piping to xargs lsd takes the lines of output from ls, in the right order, and makes them arguments for lsd.
• -U suppresses the sorting done by lsd, maintaining the order given by the order of the arguments.
• -d makes lsd print info on a directory, rather than its contents.