cool bash tricks

Lynn David Newton wrote:
> ... there were some incompatibilities with ksh that caused
> a lot of things I was used to not to work any more, so I
> put it on the shelf as one of those things to look at "some
> day" and never got around to it. So I still use ksh. But
> maybe ksh is superior anyhow.

My impression is that the version of ksh that comes
with GNU is not very good, and bash is far preferable.

Solaris uses a sounder version of ksh, but at the
last Solaris shop where I worked the sysadmins installed
a different shell that would masquerade as ksh, bourne,
or bash depending on how it was called.