ksh incompatabilities with sh?

[Guy Harris]

> > Well, no, you really can't, not always.  There are supposedly a few real
> > live incompatibilities that may break some scripts.
> 
> I have heard this too, over the years, and would like real
> documentation on what's wrong.

All I know is that somebody tried doing exactly that (replacing "/bin/sh" with
the Korn shell) on a system with an S5R2 or later Bourne shell, and found that
a lot of his shell scripts broke.  It happened a while ago, and he doesn't
remember what broke; I didn't see much point in requesting that he go through
the whole exercise again to reconstruct the problems.  He does admit to using
the Bourne shell (and lots of other UNIX tools) in ways that most people
wouldn't think of, so it may be that he hit some corner case where the two
shells behave incompatibly.

The Korn shell (the pre-"ksh-i" version, anyway) does come with a file named
COMPATIBILITY that lists a number of "sh"/"ksh" incompatibilities.