prerm is in libtxc-dxtn-s2tc0 0~git20131104-1.1.
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 | #!/bin/sh
set -e
update-alternatives --remove \
libtxc-dxtn-x86_64-linux-gnu /usr/lib/x86_64-linux-gnu/libtxc_dxtn_s2tc.so.0
|