preinst is in netbook-launcher 2:5.10.0-0ubuntu6.
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 23 24 25 26 27 28 29 30 31 32  | #!/bin/sh
set -e
rm_conffile() {
  PKGNAME="netbook-launcher"
  CONFFILE="$1"
  if [ -e "$CONFFILE" ]; then
   md5sum="`md5sum \"$CONFFILE\" | sed -e \"s/ .*//\"`"
   old_md5sum="`dpkg-query -W -f='${Conffiles}' $PKGNAME | sed -n -e \"\\\\' $CONFFILE'{s/ obsolete$//;s/.* //p}\"`"
   if [ "$md5sum" != "$old_md5sum" ]; then
     echo "Obsolete conffile $CONFFILE has been modified by you."
     echo "Saving as $CONFFILE.dpkg-bak ..."
     mv -f "$CONFFILE" "$CONFFILE".dpkg-bak
   else
     echo "Removing obsolete conffile $CONFFILE ..."
     rm -f "$CONFFILE"
   fi
 fi
}
case "$1" in
  install|upgrade)
    if dpkg --compare-versions "$2" le "1:2.1.18-0ubuntu2"; then
      rm_conffile /etc/xdg/xdg-une/autostart/netbook-launcher.desktop
    fi
esac
exit 0
 |