anchor.diff:        path = [ pkgs.wpa_supplicant ];
   
         script = ''
  -        if [ -f /etc/wpa_supplicant.conf -a "/etc/wpa_supplicant.conf" != "${configFile}" ]
  -        then echo >&2 "<3>/etc/wpa_supplicant.conf present but ignored. Generated ${configFile} is used instead."
  +        if [ -f /etc/wpa_supplicant.conf -a "/etc/wpa_supplicant.conf" != "${configFile}" ]; then
  +          echo >&2 "<3>/etc/wpa_supplicant.conf present but ignored. Generated ${configFile} is used instead."
           fi
  +
           iface_args="-s -u -D${cfg.driver} -c ${configFile}"
           ${if ifaces == [] then ''
             for i in $(cd /sys/class/net && echo *); do
  
positive.code:               fi
              fi
            done
          '' else ''
            args="${concatMapStringsSep " -N " (i: "-i${i} $iface_args") ifaces}"
          ''}
  
negative.code: 
      # Restart wpa_supplicant when a wlan device appears or disappears.
      services.udev.extraRules = ''
        ACTION=="add|remove", SUBSYSTEM=="net", ENV{DEVTYPE}=="wlan", RUN+="/run/current-system/systemd/bin/systemctl restart wpa_supplicant.service"
      '';
    };
  
  