understanding desktop (.desktop) application launchers

[Anonymous]

The .desktop mechanism follows a “specification” published by freedesktop.org
you can read about it, in depth, here

my TL;DR overview:

within any .desktop file, as a bare minimum, three lines are needed:
( 3 as a practical consideration, not same as stated in the spec )
Name= labeltext (for the menu entry and/or the desktop icon manager also displays this string)
Exec= the commandstring to be invoked when launch the application
Type=Application

When parsed, each line represents a key : value pair.
Lines beginning with a # and blank lines are considered comments and will be ignored

^—– For a launcher residing directly on desktop, those lines contain sufficient instruction for a “desktop manager” (e.g. rox).
Additional lines will be (must be) present in order for menumaker to “recognize, and categorize” the launcher, namely:
Comment= menu hint/onhover description (not all menus display this info)
Icon= path or alias for the associated iconfile (not all menus display an icon within menu)
Categories=

note: Confusingly, the freedesktop.org-spec category “name” (and capitalization) often does not exactly match
the “category name” localized labeltext displayed within a (icewm, fluxbox, xfce, whisker) desktop menu.

By convention (practicality, rather than per-spec necessity), the following lines are often specified (by package maintainers) within .desktop files:
Terminal= value is “false”, unless launching an app which runs inside a terminal shell (implicit false, and this line may be omitted)
StartupNotify= (implicit false, and this line may be omitted)

(in)famously, the Guh-nome and KDE packagers will sometimes also declare within the .desktop files they distribute
OnlyShowIn=
This serves as an instruction to menumaker scripts/utilities, causing e.g. a “for Gnome” .desktop to be ignored when constructing a menu for other desktop environments.

FAQ:
Help! installed programblah, but it’s missing from the menu !
^—v
Check for presence of OnlyShowIn= line and, if found, outcomment (or delete) that line… then regenerate the menu.

[Anonymous]

Helpful

Up

0

::

referring back to this

When parsed, each line represents a key : value pair.

understand that a “.desktop file” (especially as provided by a package maintainer) may contain extra, or proprietary, keys+values
Lines starting with X- contain proprietary key:value declarations and
X-blahblahblah=
will be ignored by any parser which doesn’t recognize blahblahblah

MimeType=
URL=
^—– Discussion of these really doesn’t (cannot) fit within this “TL;DR”
Follow the link above, skim/read the spec, educate yourself…
and understand that YMMV ~~ not all menumaker utilities (nor window managers, nor desktop icon managers) exactly follow the freedesktop.org spec(s)

[Author]

Posts