prerm is in rhino 1.7R3-5.
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 | #!/bin/sh
set -e
if [ "$1" = "remove" ]; then
update-alternatives --remove js /usr/bin/rhino
fi
|