PREUN

/bin/sh

if [[ "$1" = "0" ]]; then
  perl -ni -e "/^DICT\s*th\s*TH\s*th_TH$/ or print" /usr/share/dict/ooo/dictionary.lst
fi

POSTIN

/bin/sh

if [[ ! -f "/usr/share/dict/ooo/dictionary.lst" ]] ||       ! grep -q "^DICT[ \t]*th[ \t]*TH[ \t]*th_TH" /usr/share/dict/ooo/dictionary.lst
then
  echo "DICT th TH th_TH" >> /usr/share/dict/ooo/dictionary.lst
fi