linux - Can history files be unified in bash?

I routinely run multiple screen sessions on my Linux desktops and servers.

A problem with this is that when I grep through my command history, I find I issued a command in a different session, and have to detach and re-attach to get that history item.

Is it possible to 'force' the differently-updated histories from multiple sessions to all go to a central history?

Answer

There are two things you need to do:

1. Insert the command shopt -s histappend in your .bashrc. This will append to the history file instead of overwriting it.


2. Also in your .bashrc, insert PROMPT_COMMAND="$PROMPT_COMMAND;history -a; history -n" and the history file will be re-written and re-read each time bash shows the prompt.

EDIT: Thanks to e-t172 for the history -n trick