anchor.diff:              (interpret-prompt-string ps2)
               "> "))))
   
  -(defvar *prompt-function* 'default-prompt)
  +(defvar *prompt-function* 'default-prompt
  +  "A function which produces the shell's prompt.
  +
  +This function should return a string.  See also: `*fresh-prompt*'.")
   
   (defun main-prompt ()
     "Return the string which should be displayed as the prompt for the
  
positive.code:   (:import-from :swank)
    (:import-from :fset)
    (:export
     #:main #:run-shell-commands-in-stream
     #:default-prompt #:*prompt-function* #:*fresh-prompt*))
  (in-package :shcl/shell/main)
  
  (optimization-settings)
  
negative.code: should be displayed.")
  
  (defun default-prompt ()
    "The default prompt function.
  
  If PS1 and PS2 are defined, they will be used as the prompt.
  Otherwise, this function uses a generic prompt."
    (if *fresh-prompt*
        (let ((ps1 (env "PS1" nil)))
          (if ps1
  