/usr/share/app-install/desktop/txtreader:txtreader.desktop is in app-install-data 0.12.04.4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | [Desktop Entry]
X-AppInstall-Package=txtreader
X-AppInstall-Popcon=53
X-AppInstall-Section=universe
Name=Txt Reader
GenericName=Txt Reader
Comment=Read text novels and more
Exec=txtreader
StartupNotify=true
Terminal=false
Type=Application
Icon=txtreader
Categories=Office;Viewer;
X-Ubuntu-Gettext-Domain=app-install-data
|