UNIX for Advanced & Expert Users

I won't dare to say for all the ksh versions there are out there, but the ones i have used (working mainly on AIX) do that automatically. Every command immediately goes into the history file and history always works on this file. It is possible to assign different history files to different shell invocations to avoid that behavior if you don't want it.

The variable "HISTFILE" controls the location of the history file (HISTSIZE controls its size in # of lines) and per default it points to "~/.sh_history". If you want separate history files for every shell you could put the following into your "~/.kshrc" file. By appending the (unique) process ID to the file name a new history file is created for every "ksh" invocation:

Code:

HISTFILE="${HOME}/.sh_history_$$"

I hope this helps.

bakunin

pdksh, like bash, is writing the history file at shell exit when HISTFILE is set. By default, it is not even saving its history.

Real ksh (ksh88 & ksh93) are doing synchronous history writes so are not suffering bash/pdksh annoying behavior.