anchor.diff:  (define-command :cd (arg)
     (uiop:chdir arg))
   
  -(define-command :pwd (arg)
  -  (declare (ignore arg))
  +(define-command :pwd (_)
     (uiop:getcwd))
   
   ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  
positive.code:          (pathname-length (length (namestring path))))
      (loop
        :for pathname :in (cl-fad:list-directory path)
        :for name := (subseq (namestring pathname) pathname-length)
        :when (eql 0 (search text name))
        :collect name)))
  
  
negative.code: 
  (defmacro define-command (name parms &body body)
    `(setf (gethash ',name *command-table*)
           #'(lambda ,parms (declare (ignorable ,@parms)) ,@body)))
  
  (defun call-command (cmd arg)
    (funcall (gethash cmd *command-table*) arg))
  