Using readline with Emacs shell or eshell or ???

[Robert L. Knighten]

I am writing a command line program in which I want to have command line
editing, command and argument completion, history, etc.  The GNU Readline
package does this quite nicely, BUT my users will often actually want to
invoke the program inside the Emacs shell or perhaps eshell.  Of course
command line editing works just fine, but command and argument completion are
lost.  What is the best way of working around this?

I'm prepared to write some substantial elisp if that is the way to go.  But I
hope there is something already done.

-- Bob

-- 
Robert L. Knighten
Robert@Knighten.org