I have always known that those nice icons you can add to gnome dash-to-dock or menus where created as .desktop files somewhere. Today I decided to solve an annoying bug that led Seafile to render giantly on my full HD notebook, and after some research I discovered that was due to QT5 being too smart on enabling HiDPI on my laptop screen. So first, I had to create a shell script to trigger the seafile-applet command passing to it some environment variables first. The script is here: https://raw.githubusercontent.com/tiagoprn/bin_public/master/seafile-applet.sh Then, I copied it to /usr/bin and set it as executable with chmod. That part done, now I needed to edit the Seafile applet desktop launcher to use the shell script instead of the usual command. Then I learn that the .desktop files are all kept here: /usr/share/applications Then, it was easy. All I had to to was change seafile.desktop to launch my shell script:

[Desktop Entry]
Name=Seafile
Comment=Seafile desktop sync client
TryExec=seafile-applet.sh
Exec=seafile-applet.sh
Icon=seafile
Type=Application
Categories=Network;FileTransfer;

Another lesson learned. :) IMPORTANT: for your user the .desktop files are read from: ~/.local/share/applications.