env-paths
Get paths for storing things like data, config, cache, etc
xdg-app-paths
Determine (XDG-compatible) paths for storing application files (cache, config, data, etc)
xdg-portable
Determine XDG Base Directory paths (OS/platform portable)
commondir
compute the closest common parent for file paths
common-path-prefix
Computes the longest prefix string that is common to each path, excluding the base component