Term::ReadLine::Gnu (TRG) is an implementation of the interface to
the GNU Readline Library.  This module gives you input line editing
facility, input history management facility, word completion
facility, etc.  It uses the real GNU Readline Library and has the
interface with the almost all variables and functions which are
documented in the GNU Readline/History Library.  So you can program
your custom editing function, your custom completion function, and
so on with Perl.  TRG may be useful for prototyping before programming
with C.