Renaming file in directory

quotidie_rename

#!/usr/bin/env ruby

# vedi gist at https://gist.github.com/masciugo/9319a809efb6fdff5307
require 'rubygems'
require 'byebug'
require 'logger'
require 'fileutils'

target_dir = case ARGV.size
when 0
  File.join(ENV['HOME'],'Downloads')
when 1
  ARGV.first
else #usage
  puts
  puts
  puts "usage: ./quotidie_rename.rb <target_dir_path>"
  exit 0
end

raise "directory #{target_dir} not existing" unless File.exists? target_dir

TR = {
  'cds' => 'Corriere della Sera',
  'gds' => 'Gazzetta dello Sport',
  'mf' => 'Milano Finanza',
  's24h' => 'Sole 24 Ore',
  'fatto' => 'Fatto Quotidiano',
  'stampa' => 'Stampa',
  'foglio' => 'Foglio',
  'vdr' => 'Venerdi di repubblica',
  'venerdi' => 'Venerdi di repubblica',
  'internazionale' => 'Internazionale',
  'ac_' => 'Altro Consumo',
  'espresso' => 'Espresso',
  'manifesto' => 'Manifesto',
  'libero' => 'Libero',
  'repubblica' => 'Repubblica'
}
REGEXP = /(#{TR.keys.join('|')})(.+)\.pdf\Z/i
REGEXP_DATE = /\A\d{8}\Z/
REGEXP_NUM = /n\.\d+/i

Dir.chdir(target_dir) do |variable|
  puts "reading directory #{target_dir}"
  Dir.glob('*.pdf') do |fn|
    begin
      if data = REGEXP.match(fn)
        
        name = TR[data[1].downcase]

        suffix = if REGEXP_DATE.match(data[2])
          Date.parse(data[2]).to_s
        elsif REGEXP_NUM.match(data[2])
          REGEXP_NUM.match(data[2]).to_s
        else
          data[2]
        end

        new_fn = [name,suffix].join(' - ') + '.pdf'
        
        if File.exists? new_fn
          puts "skipping #{fn}. Already exists"
        else
          puts "RENAMING #{fn} to #{new_fn}"
          FileUtils.copy(fn,new_fn)
        end
      else
        puts "skipping #{fn}"
      end
      
    rescue SystemExit
      exit 0
    rescue Exception => e
      puts "Problem with file #{fn}, skipped. Backtrace:"
      puts e.backtrace
    end
  end
end