Turn flushing history in ksh after each command (or stop refreshing it)

Question

I have read that ksh, in contrary to bash, flushes its history after each command. This may be good for many, but for me, it drives me nuts!

I have several windows opened that are opened for their own tasks, and this history being shared messes up with specific session history of commands.

Is there a way I could disable this flushing, so the history could be appended to the command history at the logout time only?

Or, maybe there is a way to request history not to refresh command line history each time?

Answer 1

I used to have multiple shells running in screen. In my .khsrc I would customize several settings, including $PS1 and $HISTFILE (and include the basename of the tty device).

This was relatively easey to reconstruct:

tty=$(basename $(tty))
histdir=~/.hist
mkdir -p $histdir
export HISTFILE=$histdir/history.$tty
export PS1=$USER@'$PWD ['$tty'] ${?#0}$ '
exec /usr/bin/ksh

Save this as ~/bin/screenshell, and run chmod +x ~/bin/screenshell. Now you can run screen and have separate history files for each window.

SHELL=~/bin/screenshell screen

Examples:

Window 3

    vagrant@/home/vagrant [3] 127$ history
    1       history
    2       error
    3       history

Window 4

    vagrant@/home/vagrant [4] $ history
    1       history
    vagrant@/home/vagrant [4] $ echo $HISTFILE
    /home/vagrant/.hist/history.4
    vagrant@/home/vagrant [4] $ tty
    /dev/pts/4

An alternative would be to run exec ksh from .kshrc, but you'll need some kind of test to prevent an exec-loop.