anchor.diff:    (println (format "\nERROR: Unknown command '%s'." cmd))
     (usage script))
   
  -(define (display-missing-subcmd cmd subcmd script)
  -  (println (format "\nERROR: Command '%s' is missing required subcommand."
  -                   cmd)))
  +(define (display-missing-subarg cmd script)
  +  (println (format "\nERROR: Command '%s' is missing a required argument."
  +                   cmd))
  +  (usage script))
   
  -(define (display-unknown-subcmd cmd subcmd script)
  -  (println (format "\nERROR: Unknown subcommand '%s' for command '%s'."
  -                   subcmd cmd)))
  +(define (display-unknown-subarg cmd subarg script)
  +  (println (format "\nERROR: Unknown argument '%s' for command '%s'."
  +                   subarg cmd))
  +  (usage script))
   
   ;;;>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
   ;;; Supporting functions
  
positive.code:         (cmd-args (rest opts)))
      (case cmd
        ("scan" (display-access-points))
        ("join" (join-access-point cmd-args))
        (true (display-unknown-cmd cmd script))))
    (exit))
  
  
negative.code: (define (display-access-points)
    (! "nmcli device wifi list"))
  
  (define (join-access-point cmd-args script)
    (if (= cmd-args '())
       (display-missing-subarg "join" script))
    (let ((ssid (first cmd-args))
          (cmd-args (rest cmd-args)))
      (println (format "Connecting to SSID %s ..." ssid))
  