Desktop Entries

Contents

Desktop Entries store application metadata.

Sources

Desktop file content

A simple example

[Desktop Entry]
Name=MyProg
Comment=A life saver program
Exec=/foo/bar/baz
StartupNotify=true
Terminal=false
Type=Application
Icon=/foo/bar/icon

A more complex example (from the specification)

[Desktop Entry]
Version=1.0
Type=Application
Name=Foo Viewer
Comment=The best viewer for Foo objects available!
TryExec=fooview
Exec=fooview %F
Icon=fooview
MimeType=image/x-foo;
Actions=Gallery;Create;

[Desktop Action Gallery]
Exec=fooview --gallery
Name=Browse Gallery

[Desktop Action Create]
Exec=fooview --create-new
Name=Create a new Foo!
Icon=fooview-new

Desktop files databases

The desktop files are stored inside well known directories: the desktop files databases.

Databases locations

at system level : $XDG_DATA_DIRS/applications → /usr/local/share/applications and /usr/share/applications
at user level : $XDG_DATA_HOME/applications → ~/.local/share/applications

And also...

/usr/share/xfce4/applications
/usr/share/xubuntu/applications

mimeinfo.cache

Each database ows a mimeinfo.cache file, generated by update-desktop-database command which parses all the desktop entries files inside the database. This lookup table provides:

the list of desktop files associated for every MIME type. Here are a few examples:
- application/csv=libreoffice-calc.desktop;
- application/ogg=audacity.desktop;org.xfce.Parole.desktop;vlc.desktop;
- application/rss+xml=firefox.desktop;
the list of desktop files associated for every scheme handler (a particulat MIME type, which uses the special x tree). Here are a few examples:
- x-scheme-handler/http=firefox.desktop;
- x-scheme-handler/https=firefox.desktop;
- x-scheme-handler/magnet=transmission-gtk.desktop;
- x-scheme-handler/mailto=thunderbird.desktop;

Other files

defaults.list

defines default desktop file for every mimetype
to be updated by hand
IMPORTANT : it's often a symbolic link!
- /usr/share/applications/defaults.list → /etc/gnome/defaults.list
- /usr/share/xfce4/applications/defaults.list → /etc/xfce4/defaults.list
- /usr/share/xubuntu/applications/defaults.list

→ I'm not sure it is used intensively...

bamf-2.index

website
file for the bamfdaemon (aka Window matching library)
probably used by Unity...

Executables

update-desktop-database: generates mimeinfo.cache file
desktop-file-edit: helper tool for updating fields inside a desktop file
desktop-file-install: installs/updates a desktop file
desktop-file-validate: validate desktop entry files according to the Desktop Entry specification

exo-utils package provides exo-desktop-item-edit, which eases a lot desktop entries editing.

Backlinks: Desktop environments:Freedesktop specifications:Mime types