Encode set changing methods

codeset.rb

#!/usr/bin/env ruby
# Codeset changing methods

begin
  require 'rchardet'
rescue LoadError
  
end

module CodesetChange
  module_function
  
  def file_rename(a,b,force=false)
    unless File.exist? b or force
      File.rename a, b
    else
      raise Errno::EEXIST.new b
    end
  end

  def character_escape(str)
    str
      .gsub(/%([0-9A-F]{2})/){ $1.to_i(16).chr }
      .gsub(/\\([0-7]{3})/){ $1.to_i(8).chr }
  end
  
  def decode(str, encoding, default_coding = Encoding.default_external)
    encoding = CharDet.detect(str)["encoding"] unless encoding
    str.force_encoding(encoding).encode(default_coding)
  rescue => e
    STDERR.puts "\x1b[31m#{str}\x1b[0m cannot encode as #{encoding}"
    raise e
  end
  
  def change_name(path, opts)
    unless File.exist?(path || '')
      STDERR.puts "File '#{path}' not exist"
      return
    end
    obj = File.join(
      File.dirname(path),
      decode(character_escape(File.basename(path)), opts[:encoding], opts[:outcoding])
    )
    return if obj == path
    file_rename(
      path,
      obj
    )
  rescue => e
    STDERR.puts "File \n  '#{File.dirname(path)}'\n  '#{File.basename(path)}' \n  cannot encode to #{opts[:encoding]}"
    STDERR.puts e
  end
  
  def recursion(dir, opts)
    unless File.directory? dir
      STDERR.puts "File '#{dir}' not exist or not directory"
      return
    end
    root_no_dir = if opts[:no_this_dir]
      opts[:no_this_dir] = false
      true
    else
      false
    end
    Dir.foreach dir do |c|
      next if c == '.' or c == '..'
      p = File.join(dir,c)
      if File.directory? p
        recursion p, opts
      else
        change_name(p, opts)
      end
    end
    change_name(dir, opts) unless root_no_dir
  end
  
end

if __FILE__ == $0
  require 'optparse'
  options = {
    :outcoding => Encoding.default_external
  }
  optdir = nil
  OptionParser.new do |opts|
    opts.banner = "Usage: codeset.rb [options]"
    
    opts.on( "-d", "--directory DIR", "Directory input" ) do |dir|
      optdir = dir
    end
    
    opts.on( "-D", "--directory-without-self [DIR]", String,
             "Directory input (recursion without itself)" ) do |dir|
      options[:no_this_dir] = true
      optdir = dir if dir
    end
    
    opts.on( "-e", "--encoding [Encoding]", "Encoding Method" ) do |opt|
      options[:encoding] = opt ? Encoding.find(opt) : Encoding::UTF_8
    end
    
    opts.on( "-o", "--output-encoding [Encoding]", "Set output Encoding" ) do |opt|
      options[:outcoding] = opt ? Encoding.find(opt) : Encoding::UTF_8
    end
    
    opts.on( "-h", "--help", "Prints this help" ) do
      puts opts
      exit
    end
    
  end.parse!
  unless options[:encoding]
    if defined? CharDet
      STDERR.puts "no encoding unsured, use autodetecting..."
    else
      STDERR.puts "if you want to use autodetecting"
      STDERR.puts "    `gem install rchardet`"
      STDERR.puts "no encoding unsured, exit!"
      exit
    end
  end
  optdir ? CodesetChange::recursion(optdir, options) : ARGV.map{|e| CodesetChange::change_name(e, options)}
end