Enabling Command-Line Editing

You can enable command-line editing in several ways. First, if $FCEDIT, $EDITOR, or $VISUAL is set in the shell from which dbx is started, its value is checked. If the last component, the component after the last slash, contains the string emacs, then emacs-mode is enabled. If it contains vi, vi-mode is enabled. If none of the three environment variables is set or if the first one in the list that is set does not contain emacs or vi, then command-line editing is disabled.

You can enable emacs mode or vi mode from the command line or in your .dbxrc file:

set -o emacs
set -o vi

To disable command-line editing:

set +o emacs +o vi