bash_history advanced cleanup

.bashrc

# http://stackoverflow.com/questions/338285/prevent-duplicates-from-being-saved-in-bash-history
# remove duplicates while preserving input order
function dedup {
   #awk '! x[$0]++' $@
   tac $@ | awk '! x[$0]++' | tac
}

# removes $HISTIGNORE commands from input
function remove_histignore {
   if [ -n "$HISTIGNORE" ]; then
      # replace : with |, then * with .*
      local IGNORE_PAT=`echo "$HISTIGNORE" | sed s/\:/\|/g | sed s/\*/\.\*/g`
      # negated grep removes matches
      grep -vx "$IGNORE_PAT" $@
   else
      cat $@
   fi
}

# clean up the history file by remove duplicates and commands matching
# $HISTIGNORE entries
function history_cleanup {
   local HISTFILE_SRC=~/.bash_history
   local HISTFILE_DST=/tmp/.$USER.bash_history.clean
   if [ -f $HISTFILE_SRC ]; then
      \cp $HISTFILE_SRC $HISTFILE_SRC.backup
      #Via gli spazi alla fine del file
      sed -i "s/ *$//" $HISTFILE_SRC
      dedup $HISTFILE_SRC | remove_histignore >| $HISTFILE_DST
      \mv $HISTFILE_DST $HISTFILE_SRC
      chmod go-r $HISTFILE_SRC
   fi
}

# clean bash history when starting a new interactive shell
case "$-" in
    *i*) history_cleanup
esac