ksh bad for root?

[John Stafford]

There was a version of the HP-UX operating system that had a
"misfeature" in ksh that would make your life unpleasant when you tried
to shut the system down as root, if ksh was your shell, and job control
was enabled.  I don't remember the exact details, but you ended up, I
think with two shells trying to talk to your terminal.  It wasn't the
most horrible of defects, but it wasn't any fun to run into when trying
to shut your system down, especially if you were trying to deal with
some other sort of problem.

The current version of HP-UX (version 7.0) does not have this defect (to
the best of my knowledge).

Other than that, if HISTFILE is defined, and you are logged in as root
using ksh to repair file systems, the writing of the history file could
interfere with your repair.  By default, ksh being run by root is not
supposed to write history, you have to set HISTFILE before ksh starts
(or in .profile) to make it happen (and you obviously don't want to do
it if your filesystems are sick).  Don't everybody tell me that ksh
doesn't handle history files right and/or that root can write history
files without HISTFILE set but can't edit them; I believe you, I just
suspect that some ksh's are buggier than others (and I still like it).