Listing 1: NS shell script

  #!/bin/sh

  if [ "$#" -eq 0 ]
      then
        echo
        echo the syntax of the NS command is:
        echo
        echo "  NS debug ON debugging-level - set the debugging level"
        echo "  NS debug OFF                - turn off debugging"
        echo ""
        echo "  NS dump                     - dump the database"
        echo "  NS reload                   - reload the database"
        exit
  fi

  count=$#
  arg1=$1
  arg2=$2
  arg3=$3

  case "$1"
  in

    debug ) echo setting the debug
             case "$2"
             in
                on ) echo set debbugging on at $3
                     if [ "$arg3" -eq "" ]
                       then
                          count=1
                       else
                          count=$arg3
                     fi

                     echo increasing the debug level by $count
                     while [ "$count" -gt 0 ]
                       do
                         kill -USR1 `cat /etc/named.pid`
                         count=`expr $count - 1`
                       done

                    ;;
                off ) echo set debugging off
                      kill -USR2 `cat /etc/named.pid`
                    ;;
             esac
           ;;

    dump )  echo Dumping the database, see /usr/tmp/named_dump.db
            kill -INT `cat /etc/named.pid`
           ;;

    reload ) echo Reloading the database......
            kill -HUP `cat /etc/named.pid`
           ;;

  esac
