Bash – How to stop bash editing the history when I reuse and modify an entry

bashcommand historyline-editor

Some instances of bash change the command history when you re-use and edit a previous command, others apparently don't. I've been searching and searching but can't find anything that says how to prevent commands in the history from being modified when they're reused and edited.

There are questions like this one, but that seems to say how to cope with the history being edited. I've only recently come across an instance of bash that does edit the history when you reuse a command – all previous bash shells I've used have (as far as I've noticed) been configured not to change the history when you reuse and edit a command. (Perhaps I've just not been paying proper attention to my shell history for the past 15 years or so…)

So that's probably the best question: CAN I tell bash NEVER to modify the history – and if so, how?

Best Answer

Turns out revert-all-at-newline is the answer. I needed to include set revert-all-at-newline on in my ~/.inputrc file, since using the set command at the bash prompt had no effect. (Then, of course, I had to start a new shell.)

Also, I found that ~/.inputrc is loaded instead of /etc/inputrc if present, which means that any defaults defined in the latter are no longer active when you create ~/.inputrc. To fix this, start ~/.inputrc with $include /etc/inputrc.

Thanks to @StéphaneChazelas for pointing me in the right direction.

Related Solutions

Bash – sharing or synchronizing history between Zsh and Bash

If you are using the defaults for bash and zsh:

$ cat ~/.histfile >> ~/.bash_history
$ youreditor ~/.zshrc
# Here change your config to:
HISTFILE=~/.bash_history
$ rm ~/.histfile

Now you have the same file for history in both shells.

Bash – How to protect against purge of bash history

The source of the race condition is because bash only writes the history file as the shell exits. Plus it will over write the existing history file if multiple shells are running, only the last to exit will dominate the history.

So one solution is to write history out, after EVERY command. There or some negative consequences to this, such as you'll be able to up arrow history events occurring in other windows, and therefor will expose to all open shells (that you own) what commands you just ran. The most likely place this will bite you is if you are doing a repetitive set of commands, like 'up arrow N times, then hit enter' over and over again. If in a closed window a background process ends, then suddenly you'll need to pay closer attention what command is really 'up arrow N+1 times' risking running the wrong command.

To turn 'history on with every command' try adding these to you .bashrc (number of lines of history to store are just examples, you can change them for your comfort)

HISTFILESIZE=400000000
HISTSIZE=10000
PROMPT_COMMAND="history -a"
export HISTSIZE PROMPT_COMMAND

shopt -s histappend

Best Answer

Related Solutions

Bash – sharing or synchronizing history between Zsh and Bash

Bash – How to protect against purge of bash history

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