# Linux Shortcut Specification If you edit a desktop launcher or shortcut on Linux, you might see a command like this: ``` text /usr/lib/firefox/firefox %u ``` The first part is a path to the Firefox executable. This is the application that runs. And if pasted into a terminal, that path would start Firefox on its own. The second part is specific to launchers. It is part of the Desktop Entry Specification. Specifically, these are fields codes for the Exec key. For example, %u represents a single URL which makes sense since Firefox might be receiving a URL from the desktop environment while launching. This placeholder in the launcher represents the URL. So, for example, if I wanted to add a parameter to the launcher, I would add it before the URL. Typically, the file or URL is provided last. ``` text /usr/bin/vivaldi-stable --disable-gpu %U ``` You can find a link to the field codes below. ## References => https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html#exec-variables Exec Key | Desktop Entry Specification Created: Thursday, April 28, 2022 Updated: Thursday, April 28, 2022