Ubuntu – Desktop Files don’t seem to use $PATH correctly

12.10desktopenvironment-variableslauncherunity

I am creating .desktop files for use in the Unity Launcher.

I have my own location in my home directory where I put my executables (~/usr/bin/) which is correctly added to my PATH environment variable in my .pam_environment file as specified in the relevant Ubuntu documentation.

This is the contents of my .pam_environment file:

LANGUAGE=en_AU:en_GB:en
LANG=en_AU.UTF-8
LC_NUMERIC=en_AU.UTF-8
LC_TIME=en_AU.UTF-8
LC_MONETARY=en_AU.UTF-8
LC_PAPER=en_AU.UTF-8
LC_NAME=en_AU.UTF-8
LC_ADDRESS=en_AU.UTF-8
LC_TELEPHONE=en_AU.UTF-8
LC_MEASUREMENT=en_AU.UTF-8
LC_IDENTIFICATION=en_AU.UTF-8

PATH DEFAULT=${PATH}:~/usr/bin/

Which results in my PATH variable being as follows:

ben@ben-HPdv6:~$ echo $PATH
/usr/lib/lightdm/lightdm:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:~/usr/bin/:~/usr/bin/

I know it is appended twice, but anything in the .pam_environment file seems to get added twice no matter what when using the correct syntax recommended in that Ubuntu Documentation I have referenced.

This is one example of the problem (it happens with all cases). I have a script (called eclipse) in ~/usr/bin/ which runs Eclipse IDE.

I can open any terminal and simply type eclipse and it runs fine like you would expect.

But when using the following .desktop file:

#!/usr/bin/env xdg-open

[Desktop Entry]
Version=1.0
Type=Application
Terminal=false
Name=Eclipse - Juno (4.2)
Icon=/home/ben/.icons/eclipse.svg
Exec=eclipse

I get the error:
Error

But when I change the Exec= line to:

Exec=/home/ben/usr/bin/eclipse

it works perfectly.

The Official Unity Launchers and Desktop files documentation suggests that this should work:

Exec is the path to the executable file. The full path to the executable file must be used only in case it isn't in any of the paths specified in the $PATH variable. For example, any files that are inside the path /usr/bin don't need to have their full path specified in the Exec field, but only their filename.

Any suggestions on what is happening?

Best Answer

The tilde doesn't get expanded in .pam_environment the way it would in a profile script, and desktop files don't do shell expansion on their Exec lines the way the shell would, so it's looking for a file that's literally named ~/usr/bin/eclipse, which of course doesn't exist.

Replace the tilde in the PATH assignment with ${HOME} and it seems to work.

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