anchor.diff:  	((null ch) (close str) (sys:os-wait)) (write-char ch)))
     #+cmu  (ext:run-program command-str nil :output t)
     #+mcl  (ccl:run-program command-str nil :output t)
  -  #+sbcl (sb-ext:run-program command (list "-p" command-str) :output t :search t)
  +  #+sbcl (sb-ext:run-program command-str (list "-p" command-str) :output t :search t)
     #+gcl  (lisp:system command-str)
     #+clisp (ext:run-program command-str )
     #-(or cmu mcl sbcl allegro gcl) (format nil "Not yet implemented"))
  
positive.code: 	 #+sbcl      (sb-unix:posix-getcwd)
  	 #+gcl       (system-short-str #+unix "pwd" #-unix "cd")
  	 #+clisp     (ext:default-directory)
  	 ))
      (if (pathnamep dir)
  	(pathname-directory-string dir)
  	dir)))
  
  (defun pathname-directory-string (p)
    (let* ((dirnames (pathname-directory p))
  
negative.code: (defun current-directory ()
    ;; we need consistency: all pathnames, or all strings, or all lists
    ;; of strings, ...
    (let* ((dir 
  	 #+allegro   (excl::current-directory) ; pathname
  	 #+Lispworks (hcl:get-working-directory) ; ??       (current-pathname)
  	 #+mcl       (ensure-final-slash (ccl::current-directory-name))	; ??
  