.sh file on Startup Applications isn't executed

Question

This is a followup to a question about dialog boxes.

I want to show a dialog box both at the start of a session, and after n minutes of inactivity. I have decided to use zenity and xautolock. I have success invoking both from the command line (bash).

zenity --text=text --warning
xautolock -time 15 -locker "zenity --text=sometext --warning"

However, there are some constraints:

• The text has multiple words. If it has spaces, zenity will only show the first word and try to parse the other words as parameters. To fix this, I enclose the text in double quotes ("), but it leads to:
• xautolock takes the entire zenity command as an option for its -locker parameter. The command has multiple words, so I have to enclose it in quotes. But it already had quotes originally, so it conflicts on quotes-inside-quotes.
• I want the alert text to be customizable, so I'm using --text="$(cat .filename)".

So now what I have is:

zenity --text="$(cat .filename)" --warning
xautolock -time 15 -locker "zenity --text=\"$(cat .filename)\" --warning"

If I run each line separately on a terminal session (bash), they do work. The cursor gets stalled waiting for the process to terminate, but the dialog boxes are displayed the way I need them.

Now I need it to start automatically with no user intervention. What I did:

• I've put each line separetedly on the Startup Applications list. Instead of showing the desired text, they will show $(cat on the dialog box.
• I created a command.sh file on my ~ folder, pasted these two lines, made it executable.
• Running the script from the command line works.
• Puting ~/command.sh as an entry on Startup Applications does not work. Nothing happens, nothing is displayed, no error message, nothing. According to this answer, it should work.
• Putting /home/username/command.sh does work, but this user is just a "skel" that gets copied to a guest user folder created upon login, so the username folder will be "guest-RANDOMSTRING", and I can't set is as a Startup Applications entry. For permission reasons, I can't set in to the "skel" user as well.

Answer 1

Try putting them in a script and adding that script as the entry in your Startup Applications. It's hard enough to use environment variables and ~ in desktop files, let alone full-fledged command substitution, as evinced by Desktop Files don't seem to use $PATH correctly and How to include environment Variable in launcher for icon.

Answer 2

Turns out each entry on the Startup Applications list gets created as a .desktop file on ~/.config/autostart$.

As mentioned by both @muru's answer and an answer on the question he linked, .desktop files don't expand the tilde as the shell would. Neither they seem to have the ${HOME} variable.

So the solution was to add the following line to the ~/.pam_environment file:

PATH DEFAULT=${PATH}:${HOME}/scripts

Then place my .sh script on the ~/scripts folder, and add script.sh, no prefixes, to the Startup Applications list.