remove duplicate lines of current bash_history #bash #sh #macOS #linux #bash_history

undupe_bash_history.sh

#!/usr/bin/env bash
## https://superuser.com/questions/722461/how-can-you-remove-duplicates-from-bash-history
## It is possible to remove duplicated lines which are already in .bash_history by running
echo bash_history - remove duplicated lines
echo --------------------------------------
echo first back it up
date_now=$(date +"%Y-%m-%d-%H%M%S")
cp ~/.bash_history ~/bash_history.old_$date_now 
echo removing duplicate lines
nl ~/.bash_history | sort -k 2  -k 1,1nr| uniq -f 1 | sort -n | cut -f 2 > ~/unduped_history
echo copying over old history file
cp ~/unduped_history ~/.bash_history