I'm running KSH on RHEL 2.6 on x86. KSH version is:
sh (AT&T Research) 93u+ 2012-08-01
Switching to Bash or back to Tcsh (which I happily used at my old job) is not possible.
The first annoying thing I noticed about KSH is that sometimes my history from different terminals (I have many terminals open at a time) got mixed together when scrolling through history with the up key. I then learned that there's a single HISTFILE shared by all my terminals. Fine, but still weird that they weren't always getting intermixed. I also noticed the HISTFILE wasn't always updated immediately. Eventually I decided that KSH was probably buffering some command history and periodically flushing the contents to HISTFILE. I couldn't find that behavior documented anywhere but it seems like a reasonable explanation.
I really want different history for each session, so I added this to my .kshrc file:
HISTFILE=~/.hist.$(tty | sed 's;.*/;;')
which is supposed to give a unique HISTFILE per terminal. It does that, which is great. But...these HISTFILES seem to periodically get cleared. Most of mine have a file size of 0 bytes right now.
Update: The individual HISTFILEs for all my open terminals are being cleared every 10 minutes. Like clockwork.
Anybody seen this before???