Running a .desktop file in the terminal

Question

From what I can gather, .desktop files are shortcuts that allow application's settings to be customized. For instance, I have lots of them in my /usr/share/applications/ folder.

If I open that folder in nautilus, I can run these applications just by double clicking its associated file, e.g. double-clicking firefox.desktop runs Firefox. However, I can't find a way to do the same thing via terminal.

If I do gnome-open foo.desktop it simply opens foo.desktop as a text file. If I make it exectuable and then run it in bash it simply fails (which is expected, it's clearly not bash script).
EDIT: Doing exec /fullpath/foo.desktop gives me a "Permission denied" message, even if I change ownership to myself. If I make executable and do the same command, the terminal tab I'm using simply closes (I'm guessing it crashes). Finally, if I do sudo exec /fullpath/foo.desktop, I get an error reporting "sudo: exec: command not found".

That's my question, how can I run a foo.desktop file from the terminal?

Answer 1

The command that is run is contained inside the desktop file, preceded by Exec= so you could extract and run that by:

`grep '^Exec' filename.desktop | tail -1 | sed 's/^Exec=//' | sed 's/%.//'` &

To break that down

grep  '^Exec' filename.desktop  - finds the line which starts with Exec
| tail -1                       - only use the last line, in case there are multiple
| sed 's/^Exec=//'              - removes the Exec from the start of the line
| sed 's/%.//'                  - removes any arguments - %u, %f etc
`...`                           - means run the result of the command run here
&                               - at the end means run it in the background

You could put this in a file, say ~/bin/deskopen with the contents

#!/bin/sh
`grep '^Exec' $1 | tail -1 | sed 's/^Exec=//' | sed 's/%.//'` &

Then make it executable

chmod +x ~/bin/deskopen

And then you could do, eg

deskopen /usr/share/applications/ubuntu-about.desktop

The arguments (%u, %F etc) are detailed at http://standards.freedesktop.org/desktop-entry-spec/desktop-entry-spec-1.0.html#exec-variables - none of them are relevant for launching at the command line.

Answer 2

The answer should be

xdg-open program_name.desktop

But due to a bug this no longer works.

Answer 3

Addendum to Hamish's answer.

Given the deskopen script, you can use a reference to it as the shebang line in a .desktop file, since the comment character is still #. That is to say, put this as the first line of the .desktop file:

#!/usr/bin/env deskopen

Then flag the .desktop file as executable (e.g. with a chmod +x whatever.desktop), and then you can

path/to/whatever.desktop

and voilà -- The app will open! (Complete with the icon file I specified, though I have no idea how.)

Now, if you also want deskopen to pass through any command-line parameters, you can instead use this slightly-modified version:

#!/bin/sh
desktop_file=$1
shift
`grep '^Exec' "${desktop_file}" | sed 's/^Exec=//' | sed 's/%.//'` "$@" &

As an aside, I tried using "#{@:2}" instead of shifting, but it kept giving me 'bad substitution'...