preinst is in libswt-gtk-3-java 3.8.2-3.
This file is a maintainer script. It is executed when installing (*inst) or removing (*rm) the package.
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 17 18 | #! /bin/sh
set -e
case "$1" in
install|upgrade)
if update-alternatives --list swt.jar >/dev/null 2>&1 ; then
update-alternatives --remove-all swt.jar
fi
;;
*)
echo "prerm called with unknown argument \`$1'" >&2
exit 1
;;
esac
exit 0
|