The File-System

File Stats (Python API to the syscall)
`st_dev`	device ID
`st_uid`	owner's user ID
`st_gid`	owner's group ID
`st_mode`	mode, type and permission bits
`st_ino`	inode number [posix]
`st_nlink`	number of hard links
`st_size`	size (b) [regular file]
`st_atime`	last access (s)
`st_atime_ns`	last access (ns)
`st_mtime`	last content modification (s)
`st_mtime_ns`	last content modification (ns)
`st_ctime`	last metadata change (s)
`st_ctime_ns`	last metadata change (ns)
`st_birthtime`	time of creation (s) [windows]
`st_birthtime_ns`	time of creation (ns) [windows]

Symbolic vs. Hard links

The difference is best described with a diagram.

Useful local files

    find /usr/share -type f -name "*.jpg" # etc

/usr/share/mime/ contains lists of MIME formats metadata, program associations.

It is possible to style the look of Nemo changing the stylesheet under ~/.config/gtk-3.0/gtk.css

For the content of visual studio hints, tooltips, the directory hosting Visual Studio extensions, including CSS, can be found at: /usr/share/code/resources/app/extensions/ . Some content can be extracted from e.g. css-language-features/server/dist/node/85.cssServerMain.js or css-language-features/server/dist/node/920.cssServerMain.js .

backgrounds/gnome	backgrounds, .webp / .svg
pixmaps/faces	random profile pics, 512x512 .jpg
cinnamon/bumpmaps	bumpmaps for transparency effects
iso-flags-png-320x240	flags per ISO country code

Customizing Desktop Apps.

Archlinux Wiki, about Desktop entries.

Installed desktop applications keep metadata, such as attributed name, icon, etc. in /usr/share/applications. The metadata is stored within desktop entries, files with the .desktop suffix.

  find /usr/share/applications -type f \
  -name '*.desktop'

    /usr/share/applications/gnome-sound-panel.desktop
    /usr/share/applications/libreoffice-startcenter.desktop
    /usr/share/applications/gimp.desktop
    /usr/share/applications/gnome-universal-access-panel.desktop
    /usr/share/applications/gnome-user-share-webdav.desktop
    (...)

The directory contains a few non-desktop files.

  find /usr/share/applications -type f \
  -not -name '*.desktop'

  /usr/share/applications/mimeinfo.cache
  /usr/share/applications/x-cinnamon-mimeapps.list

The files associate applications and infos to MIME types. They are good parsing target to retrieve MIME metadata.

The GNU Find Utilities

The GNU Find Utilities are the basic directory searching utilities of the GNU operating system. These programs are typically used in conjunction with other programs to provide modular and powerful directory search and file locating capabilities to other commands. The tools supplied with this package are:

find - search for files in a directory hierarchy
locate - list files in databases that match a pattern
updatedb - update a file name database
xargs - build and execute command lines from standard input

`find` and `xargs` synergy.

find and xargs are combined to map found files to commands. Using a pair of flags: find ... -print0 separates results with null-bytes, and xargs -0 ... accepts null-bytes separated lists.

  find -type f -print0 | xargs -0 dirname

`xargs` to convert words and lines

    echo 'from words to lines' | xargs -n1
    from
    words
    to
    lines

A loop alternative

    echo 'from words to lines' | 
    while read -r line; do
      for word in $line; do echo "$word"; done
    done

Subdirectories by descending disk usage.

  du -s * | sort -nr