The FreeDesktop specifications are used by GNOME, KDE, and Xfce, and provide your Linux desktop with a set of standard file formats for organizing desktop application menus, shortcuts, icons, and special directories. The files look like Windows .INI files, and they allow for the creation of Start menu-like shortcut menus on your desktop, like this one, seen in Xfce:

The specifications also provide a way to store a URL shortcut in a file. We can use this method to store hyperlinks along with informative descriptions.

In my case, I keep my documents organized into three piles:

• ee (for electrical engineering)
• math
• eng (for other misc. engineering)

If I created folders in the Applications menu to mimick this structure, it would add bloat to that menu, and require me to re-use that menu for documents, which I'd prefer not to do. If I'm retrieving these documents often, it's faster for me to put them inside their own menus next to Applications on the dockbar itself. Essentially, make them root menus of their own.

<Menu>
  <Name>math</Name>
  <Directory>math.directory</Directory>
  <AppDir>/home/joya/.local/share/applications/mylibrary/math</AppDir>
  <DirectoryDir>/home/joya/.local/share/desktop-directories/mylibrary/math</DirectoryDir>
      
  <Include>
    <Filename>MatrixCookbook.desktop</Filename>
    ...

  </Include>
            
  <Menu>
    <Name>Feedback Systems: An Introduction</Name>
    <Directory>Feedback Systems: An Introduction.directory</Directory>
    <AppDir>/home/joya/.local/share/applications/mylibrary/math/Feedback Systems: An Introduction</AppDir>
    <DirectoryDir>/home/joya/.local/share/desktop-directories/mylibrary/math/Feedback Systems: An Introduction</DirectoryDir>
    
    <Include>
      <Filename>1st-ed.desktop</Filename>
      <Filename>fbs-frontmatter_30Sep18.desktop</Filename>
      <Filename>fbs-ch7-state-feedback.desktop</Filename>
      <Filename>fbs-ch2-feedback-principles.desktop</Filename>
      ... 

[Desktop Entry]
Encoding=UTF-8
Icon=folder
Type=Directory
Name=math
Comment=Documentation Directory

[Desktop Entry]
GenericName=File link
Icon=evince
URL=file:///home/joya/read/math/MatrixCookbook.pdf
Type=Link
Name=MatrixCookbook.pdf]

Before looking at the script [4] itself, there's a few directories that FreeDesktop reads that you'll have to know about. We'll be creating .menu and .directory files for each library file, and .desktop files for each library file.

So running build-mylibrary.pl ~/read/ee will create ee.menu and ee.directory and the same for all its subfolders and files. Here's a breakdown of what and where each file will be created.

The structure of the script is fairly straightforward (as Perl6 goes). We define a Menu class to retain all the meta information associated with a folder/menu. Then there are two visitor functions: one for folders and one for files. The main flow of execution is then to simply visit every file and folder under some named library folder.

My own library folders exist at $HOME/read/<name> with my largest being the ee library that contains all of my electrical component datasheets.

The only files you work with after the script has been run are the .menu files: you just need to tell your desktop environment where they are in order to have them appear. Everything else is internally cross-referenced with these .menu files describing the top level.

If that isn't enough, the rest of this article provides a little walk-through of making that part work.

Right-click on blank area of any desktop panel or on one of its existing launchers to get a floating menu. From that menu, choose Panel ▶ ➕Add New Items... then pick Applications Menu and the button Add.

You'll then notice a familiar prefab Applications Menu appear at the far right of your panel. Right-click on it and select Properties.

Here you can decide on the "look and feel" of your new Applications Menu. Since it's going to be a top level library folder and you might have several of these, I choose to leave out the button title and to only Show icons in menu.

Finally, near the bottom, you'll want to choose Use custom menu file and use the file chooser to select the .menu file that was generated under $HOME/.config/menus. Then hit close.

That's it! An entire library folder is now accessible from your desktop.

One small caveat: whenever you call the script to regenerate the file, you'll get a little message from the panel app saying that it failed to load the menu. This is because when you regenerate, it loses track of the old file. Simply go into the panel preferences, briefly select the Menu File radio button for Use the default menu, and then click it back to Use custom menu file again. Now your menu file will be reloaded by the panel applet.