bash – Preserve Bash History in Multiple Terminal Windows

bashcommand history

I consistently have more than one terminal open. Anywhere from two to ten, doing various bits and bobs. Now let's say I restart and open up another set of terminals. Some remember certain things, some forget.

I want a history that:

Remembers everything from every terminal
Is instantly accessible from every terminal (eg if I ls in one, switch to another already-running terminal and then press up, ls shows up)
Doesn't forget command if there are spaces at the front of the command.

Anything I can do to make bash work more like that?

Best Answer

Add the following to your ~/.bashrc:

# Avoid duplicates
HISTCONTROL=ignoredups:erasedups
# When the shell exits, append to the history file instead of overwriting it
shopt -s histappend

# After each command, append to the history file and reread it
PROMPT_COMMAND="${PROMPT_COMMAND:+$PROMPT_COMMAND$'\n'}history -a; history -c; history -r"

Related Solutions

Mangled history

It depends entirely on how the shell chooses to handle it

bash by default will overwrite the history file with the local history of each shell as it exits, so the last shell to exit wins. The histappend option will cause it to append to the master history instead (shopt -s histappend).

zsh does the same by default, and has a few options for dealing with it:

appendhistory -- The history of each shell is appended to the master history file as the shell exits
incappendhistory -- The master history file is updated each time a line is executed in any shell, instead of waiting until that shell exits
sharehistory -- Like incappendhistory, but also pulls changes from the master history file into all running shells, so you can run a command in one shell and then hit Up in another shell and see it

Bash – Saving bash history from multiple Konsole not working correctly

I have concluded that it is not possible to append the new commands directly and at the same time to remove any duplicates. So my solution is to run the following command ones in a while. or to put it in my crontab.

tac $HOME/.bash_history | awk '!seen[$0]++' | tac > $HOME/.hist_Temp 
mv $HOME/.hist_Temp $HOME/.bash_history

The above command will keep the last occurrence of a command and remove every other repetitions above it from the history file without messing up the order.

Best Answer

Related Solutions

Mangled history

Bash – Saving bash history from multiple Konsole not working correctly

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