Saving bash shell history for multiple shells

The history from the commands typed into bash are very useful from time to time, especially when I think “Oh, I’ll remember that command next time I need it”, and then I don’t. The problem with bash’s history are twofold:

  • It only saves history when the terminal exits cleanly, so if your connection drops or you have to kill the current process, you lose your history.
  • If you are running multiple terminals, or using a terminal multiplexer like tmux (my favorite!) or screen, the last bash to exit overwrites any other history with its history.

So, after a little searching I’ve found a solution that works for me for now.

# Save history
#Set history suffix to the current terminal
HISTSUFFIX=`tty | sed 's/\///g;s/^dev//g'`
# All terminals' histories will be stored in separate files
# in .bash_history_log. That folder will need to be created.
# Time stamp the commands in the history file
HISTTIMEFORMAT="%y-%m-%d %H:%M:%S "
# Don't save duplicate commands
# Control the size of the file
# Bash will append to the history file
shopt -s histappend
# Bash will append to the history file after each time
# the prompt is shown. This way it's always saved.
PROMPT_COMMAND='history -a'

Put that in your .bashrc and you’re good to go. Comments are welcome!