I have following command to clear last entry of bash history(terminal history/command-line history). My Ubuntu 14.04 Trusty Tahr.
sed -i '$d' ~/.bash_history But I want to keep last 1,2...n entries and delete the rest, how can I achieve that ?
Can be with sed/history/awk or any other command, no problem as far as the requirements are met.
If you want to keep the last N lines, use tail (for example, the last 20 lines):
tail -n 20 "$HISTFILE" > ff && mv ff "$HISTFILE" I'm using the HISTFILE variable since this will always point to your history file, even if you've changed its name.
cannot open ‘/home/<user>/.bash_history’ for reading: No such file or directory. Why so ? echo "$HISTFILE" gives /home/user/.bash_history so path is correct. Also can this same thing be done with sed command ? ls -l "$HISTFILE"? It sounds like you don't have one. As for sed, no, not really. AFAIK there's no way for sed to count from the end of the file. You could reverse the file, take the top few lines and reverse it again (tac "$HISTFILE" | sed -n '1,10p' | tac > ff && mv ff "$HISTFILE" but that seems way too complicated. -rw------- 1 ubuntu ubuntu 0 Oct 4 10:44 /home/ubuntu/.bash_history for ls -l $HISTFILE but that doesn't work with tail command you gave in asnwer. It says /home/ubuntu/.bash_history’ for reading: No such file or directory. Oh didn't know tac(reverse of cat) was also there, thanks for that. ls shows the file does exist (but is empty). Something very strange is going on here. Come into /dev/chat and ping me if you want to debug it further.
sed -i '1,10!d' ~/.bash_historyreplace 10 with whatever you want to count up to.