Small IBExpert query set converter written in Ruby

ibe2txt

#!/usr/bin/env ruby

require 'ibe2txt'

begin
  if !ARGV.empty?
    if File.exist?(ARGV[0])
      if File.extname(ARGV[0]) == '.xml'
        IBE2Txt.new(ARGV[0])
      else
        puts 'Not an xml file'
        puts IBE2Txt::USAGE
      end
    else
      puts 'No such file'
      puts IBE2Txt::USAGE
    end
  else
    puts IBE2Txt::USAGE
  end
rescue StandardError => e
  puts e
  puts IBE2Txt::USAGE
end

ibe2txt.rb

# frozen_string_literal: true

require 'base64'
require 'nokogiri'

class IBE2Txt
  USAGE = 'Usage: ibe2txt file.xml'

  private

  attr_accessor :path, :doc, :captions, :sources

  def initialize(path)
    @path = path
    @captions = []
    @sources = []
    @doc = File.open(@path, 'r') { |f| Nokogiri::XML(f) }
    parse
    write_back
  end

  def parse
    @captions = @doc.xpath('/ibe_sql_queries/queryset/query/caption').map { |x| Base64.decode64(x.content) }
    @sources = @doc.xpath('/ibe_sql_queries/queryset/query/source').map { |x| Base64.decode64(x.content) }
    # puts @sources, @captions
  end

  def write_back
    File.open("#{File.join(File.dirname(@path), File.basename(@path, '.xml'))}.txt", 'w') do |f|
      @captions.zip(@sources).each do |c, s|
        line = "#{c}\n#{s}\n"
        f << line.encode(line.encoding, universal_newline: true)
      end
    end
  end
end