Example of junoser-squash.rb

junoser-squash.rb

require 'junoser'
require 'parslet'

module Junoser
  module Display
    class DeleteTransformer < Parslet::Transform
      rule(config: simple(:config)) do
        "(#{config.to_s}"
      end

      rule(config: sequence(:configs)) do
        configs.join("\n")
      end

      rule(arg: simple(:arg)) do
        arg
      end

      rule(label: simple(:label)) do
        ")#{Regexp.escape(label.to_s)}"
      end

      rule(label: simple(:label), child: simple(:child)) do
        "#{Regexp.escape(label.to_s)} #{child}"
      end

      rule(label: simple(:label), child: sequence(:children)) do
        %[#{Regexp.escape(label.to_s)} #{children.join(' ')}]
      end

      rule(statement: simple(:statement), argument: simple(:argument)) do
        "#{statement} #{argument}"
      end

      rule(statement: simple(:statement), argument: sequence(:arguments)) do
        %[#{statement} #{arguments.join(' ')}]
      end

      rule(oneline: simple(:str)) do
        str
      end

      rule(oneline: sequence(:strs)) do
        strs.join(' ')
      end
    end

    class SetLinesWithCommands
      def initialize(io)
        @io = io
        @lines = []
        @parser = Junoser::Parser.new
        @transformer = DeleteTransformer.new
      end

      def process
        while l = $<.gets
          l.strip!

          case l
          when /^set /
            @lines << l
          when /^delete /
            to_delete = @parser.parse(l.gsub(/^delete /, 'set '))
            delete_lines @transformer.apply(to_delete)
          end
        end

        @lines.uniq.map(&:strip).join("\n")
      end


      private

      def delete_lines(pattern)
        @lines.each do |l|
          l.sub!(/#{pattern}/) { $1 }
        end
      end
    end
  end
end


lines = Junoser::Display::SetLinesWithCommands.new($<)
puts lines.process

実行例

入力ファイル (config)

set interfaces em0 unit 0 family inet address 1.1.1.1/32
set interfaces em0 unit 1 family inet address 1.1.1.2/32
delete interfaces em0 unit 0 family inet address 1.1.1.1/32

出力例

junoser $ ruby junoser-squash.rb config
set interfaces em0 unit 0 family inet
set interfaces em0 unit 1 family inet address 1.1.1.2/32