Remove duplicates in file (without sorting!) leaving the _last_ of the occurences

Following https://www.baeldung.com/linux/history-remove-avoid-duplicates , I added clean_history() { awk '!a[$0]++' $HOME/.bash_history > $HOME/.bash_history.tmp && mv $HOME/.bash_history.tmp $HOME/.bash_history } trap clean_history DEBUG # execute after every command to my ~/.bashrc file in order to ensure that after every command is executed, duplicate entries are removed. This is important for me, because kile (the KDE LaTeX editor) leaves a ton of "clear" and "cd ..." commands in the history, effectively destroying the history within a single session of LaTeX-writing. And I have not found any way to prevent kile to do that. Anyway... the above line of code effectively removes all subsequent entries of a command and leaves the first entry in the history. However, I want the _last_ entry to remain in the history and all previous entries to be deleted. How can do this? By the way: Kile ignores HISTCONTROL=ignoredups:erasedups so using this approach seems not to be an option. I would also be happy if we could prevent Kile to write into the history all together. Non-duplicates: - https://unix.stackexchange.com/questions/190919/removing-duplicate-entries-in-text-file is leaving the first entry in the file - so does https://unix.stackexchange.com/questions/525481/how-to-remove-duplicate-lines-inside-a-text-file-get-the-number-of-the-removed - https://unix.stackexchange.com/questions/20747/how-to-stop-bash-appending-history uses HISTCONTROL