Bash scripting TnT

while [ "$1" != "" ]; do
    case $1 in
          --address )
               shift
               address="$1"
               ;;
          --netmask )
               shift
               netmask="$1"
               ;;
          --gateway )
               shift
               gateway="$1"
               ;;
          --dns )
               shift
               dns="$1"
               ;;
          --show-current )
               show_current
               exit
               ;;
    esac
    shift
done