My First Vaguely Useful Ruby Script

Alright, anyone with directories full of digital photos, mp3's, or other docs might appreciate an easy way to rename all the files in a directory, either by appending a common prefix, postfix (or extension), or giving each file the same basename with a sequence appending to the filename. There have been times I would have found that useful, and it turns out it's very easy to do with some simple Ruby scripting....


file_renamer.rb

#!/usr/bin/env ruby

require 'fileutils'
require 'find'

class FileRenamer

 attr_accessor :directory

 # constructor
 def initialize(directory=".")
  @directory = directory
  FileUtils.cd(@directory, :verbose => true)
 end

 #add prefix to each file in dir, ignoring directories
 def add_prefix(prefix)
  Dir.foreach(@directory) {|x| rename_file(x,"#{prefix}#{x}") }
 end
 
 #add postfix to end of each file in dir, ignoring directories
 def add_postfix(postfix)
  Dir.foreach(@directory) {|x| rename_file(x,"#{x}#{postfix}") }
 end
 
 #rename a file unless it is a directory
 def rename_file(from, to)
  print "#{from}"
  if FileTest.directory?(from)
   puts "/ remains unchanged"
  else
   FileUtils.mv(from, to, :verbose => false)
   puts " changed to #{to}"
  end #if 
 end
 
 # rename all files in directory to base_name + a sequence
 def rename_with_base(base_name)
  idx = 0
  Dir.foreach(@directory) do |x|
   if !FileTest.directory?(x)
    rename_file(x,"#{base_name}#{idx}")
    idx += 1
   end
  end
 end
 
 def list_dir
  Dir.foreach(@directory) do |x|
   print "#{x}"
   if FileTest.directory?(x)
    puts "/"
   elsif FileTest.executable?(x)
    puts "*"
   elsif FileTest.symlink?(x)
    puts "->"
   end #if
  end #do
 end
end

# test it...
fn = FileRenamer.new("C:/test")
fn.list_dir
fn.add_prefix("test")
fn.rename_with_base("start")
fn.add_postfix(".txt")