Flush bash_history after each command

If you, like me, often work in a lot of terminals on a lot of servers, or even a lot of terminals on the same one, you may recognise the frustration of a lost bash history.
I don’t always gracefully log out of my sessions, so every so often my ~/.bash_history isn’t written and all my flashy commands are lost (the history buffer is only committed when you log out, everything that you see in `history` is not actually written to disk). I quite often find myself rewriting the same one-liners or long option list just because I closed my konsole or SecureCRT window without first logging out of all the sessions properly.

So I put some effort into finding a solution to this, and whilst reading through the bash manpage, I saw PROMPT_COMMAND. *pling*
export PROMPT_COMMAND='history -a'

To quote the manpage: “If set, the value is executed as a command prior to issuing each primary prompt.”
So every time my command has finished, it appends the unwritten history item to ~/.bash_history before displaying the prompt (only $PS1) again.

So after putting that line in /etc/bashrc I don’t have to find myself reinventing wheels or lose valuable seconds re-typing stuff just because I was lazy with my terminals.

This is one of those things that I should have done ages ago, but never took the time to.