Use LF as a Directory Tree Diff Walker

[mibli]

So I've created a simple diff walker in the spirit of ncdu, that utilizes new on-load hook, to display information about differences between previously set directories.

I guess it could be added in a wiki, however I'd need someone to guide me on how to document that properly, as it includes a rather sizable script for diff cache generation. For now I've created a gist for it:

https://gist.github.com/mibli/21fd6ebc7364e1f65bdeecad481d62b1

The solution allows inserting :start_diff $reference_directory to switch to diff mode and generate cache and then it loads the cached diff percentage into custom info on directory load.

Here's how it looks:

user@machine:~/r/i3switch/.git                                                                       
  .git                        119%    -    branches                                         100%    -  
  .github                     100%    -    filter-repo                                      100%    -  
  cpp                         100%    -    git-cliff-core                                   100%    -  
  docs                        100%    -    hooks                                            0%      -  
  python                      100%    -    info                                             50%     -  
  rust                        100%    -    logs                                             136%    -  
  scripts                     100%    -    modules                                          23%     -  
  .clang-format               0%    32B    objects                                          100%    -  
  .gitignore                  120% 213B    refs                                             122%    -  
  Makefile                    100% 799B    COMMIT_EDITMSG                                   200%  46B  
  README.md                   188% 3.5K    config                                           145% 279B  
  tags                        100% 3.1M    description                                      0%    73B  
                                           fast_import_crash_2704499                        100% 735B  
                                           fast_import_crash_3105971                        100% 465B  
                                           FETCH_HEAD                                       400%  87B  
                                           HEAD                                             200%  33B  
                                           index                                            100% 7.8K  
                                           ORIG_HEAD                                        200%  41B  
                                           packed-refs                                      121% 854B  
                                                                                                       
drwxr-xr-x 11 user user 4.0K Thu Jul  3 13:09:24 2025                                1   1/12

EDIT: I've now also added a diff previewer that will show diffs as a preview. Old previewer will be restored after stop_diff.

[CatsDeservePets]

Wow. Who could have thought that on-load and addcustominfo could be used in such such ambitious ways?

I am working on getting this to run on my machine.
Things I noticed so far:

• Path definitions are seemingly all over the place. Some inside shell scripts, some inside your example lfrc file. I would at least give a list of all the paths and where to change them to make it simpler without the need to study the whole code
• You are using #!/bin/bash as the shebang in your shell scripts. Better use #!/usr/bin/env bash for people like me that use a version different to their preinstalled one.
• Your diff_previewer script is missing a file extension, which makes it look like user_diff_previewer points to a directory rather than a shell script.