Bash History – How to Undo a Bash History Modification

bashcommand history

By pressing up, I can go through previously entered commands. I've noticed though that if I modify one of them, that alters the history. For instance, if I type:

echo a
echo b
echo c
[up][up][backspace]d[ctrl+c]

the history now shows that the second command was echo d, not echo b. How do I keep the first echo b in the history?

For instance, say I run a really long command, with a lot of options. then I want to run it again, with a minor change, so I go back through the history to find it, make the change, but then realize that actually I don't need to re-run it, having just thought of another option to do instead. then later, I want to go back and remind myself what the command I ran was – but wait, the history is now showing the wrong thing!

This comes up very rarely, but when it does I find it really irritating. Is there some way to automatically preserve the original history?

Best Answer

Try to put in your ~/.inputrc

 set revert-all-at-newline on

In some case you can find it in the default value (Off).
It should force readline to undo all changes to history lines before returning when accept-line is executed. (more info in man bash).

Edit:
CTRL+c and set revert-all-at-newline on works fine since bash-4.3.30. 

# GNU bash, version 4.3.30(1)-release
# Emacs-mode

echo c
[up][backspace]d[Ctrl+c][up] # you should see echo c

But:

echo c
[up][backspace]d[down][Ctrl+r]echo[Ctrl+j][Ctrl+c][up] # you should see echo d
Related Question