Clozure CL’s default prompt is “? “. You can customize this by setting ccl:*listener-prompt-format* to a format control of your choice.
Note that a format control “string” can be a function. Here’s an example that makes the prompt contain the current package name.
(defun prompt-formatter (stream break-level) (princ (package-name *package*) stream) (if (plusp break-level) (format stream " ~d > " break-level) (write-string "> " stream)))
To start using this, do
(setq ccl:*listener-prompt-format* #'prompt-formatter)