/usr/share/app-install/desktop/extcalc:extcalc.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 | [Desktop Entry]
X-AppInstall-Package=extcalc
X-AppInstall-Popcon=248
X-AppInstall-Section=universe
Encoding=UTF-8
Name=Extcalc
Exec=extcalc
Terminal=false
Type=Application
Categories=Qt;Utility
Icon=_usr_share_icons_icon48
X-Ubuntu-Gettext-Domain=app-install-data
|