Bash history Toolkit

Exit bash without writing anything

kill -9 $$

This is hacky and aggressive. But it’s a fun way to end an espionage session.

Clears the history of the current session, even this command itself

history -c

Disables history saving

unset HISTFILE

Reloads history from disk

history -r

Executes a commande without including it in history

echo foo bar; history -d $(history 1)

Deletes your password (a command, etc.) from your history

If all you are concerned about is getting rid of a single entry, you can use the previous example creatively. Use history to find the number of the entry to delete. Then delete it by number. For example…

$ history
  1  pwd
  2  date
  3  sudovisudo
  4  hunter2
  5  man history
  6  help history
  7  history
$ history -d 4

I hope I don’t have to tell you this, but just in case: Don’t grep history for your password. If you “really do” need to search history, do history | LESSHISTFILE=/dev/null less, and explicitly do a / search.

If you are really embarrassed and want there to be no record of you deleting something from history, you can combined this concept with the last.

history -d 4; history -d $(history 1)

Or to also get rid of the original mistake…

for n in "$(history 1)" 4 3; do history -d $n; done

Notice that you have to cycle over the entry numbers in descending order because each call to history -d pops the entry out of the list and all subsequent entries’ numbers decrease by 1. Also, you have to double quote the subshell because history 1 returns not just the number, but also the command and its arguments, and each would get a separate cycle in the for loop. But at this point this is turning into a bash lesson and I’ll stop.

#shell #bash

https://stackoverflow.com/a/52208927