Shared history in Bash

One of the features that I miss most in Bash is the shared history between terminals that Zsh supports. I was hunting down a solution for this and came across this Stack Overflow answer ¹ by user lesmana. This code snippet does the trick:

HISTSIZE=9000
HISTFILESIZE=$HISTSIZE
HISTCONTROL=ignorespace:ignoredups

history() {
  _bash_history_sync
  builtin history "$@"
}

_bash_history_sync() {
  builtin history -a         #1
  HISTFILESIZE=$HISTSIZE     #2
  builtin history -c         #3
  builtin history -r         #4
}

PROMPT_COMMAND="_bash_history_sync;$PROMPT_COMMAND"

This is very hacky—This setting overrides the shell prompt to sync history every time the prompt is loaded. But like all great hacks, it works.