preinst is in mlterm 3.3.2-1.
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 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | #!/bin/sh
set -e
case "$1" in
    install|upgrade)
        if dpkg --compare-versions "$2" lt "3.1.2-1.1" ; then
          rm -rf /usr/share/doc/mlterm || true
        fi
    ;;
    abort-upgrade)
    ;;
    *)
        echo "preinst called with unknown argument \`$1'" >&2
        exit 1
    ;;
esac
exit 0
 |