File integrity validation script written in Ruby.

changedFiles.rb

require 'find'
require 'digest/md5'

unless ARGV[0] and File.directory?(ARGV[0])
  puts "\n\n\nYou need to specify a root directory: changedFiles.rb
	<directory>\n\n\n"
	exit	
end

root = ARGV[0]
oldfile_hash = Hash.new
newfile_hash = Hash.new
file_report = "#{root}/analysis_report.txt"
file_output = "#{root}/file_list.txt"
oldfile_output = "#{root}/file_list.old"

if File.exists?(file_output)
	File.rename(file_output, oldfile_output)
	File.open(oldfile_output, 'rb') do |infile|
		while (temp = infile.gets)
			line = /(.+)\s{5,5}(\w{32,32})/.match(temp)
			puts "#{line[1]}  -->  #{line[2]}"
			oldfile_hash[line[1]] = line[2]
		end
	end
end

Find.find(root) do |file|
	next if /^\./.match(file)
	next unless File.file?(file)
	begin
		newfile_hash[file] = Digest::MD5.hexdigest(File.read(file))
	rescue 
		puts "Error reading #{file} --- MD5 hash not computed."
	end
end

report = File.new(file_report, 'wb')
changed_files = File.new(file_output, 'wb')

newfile_hash.each do |file, md5|
	changed_files.puts "#{file}    #{md5}"
end

newfile_hash.keys.select { |file| newfile_hash[file] == oldfile_hash[file]
}.each do |file|
	newfile_hash.delete(file)
	oldfile_hash.delete(file)
end

newfile_hash.each do |file, md5|
	report.puts "#{oldfile_hash[file] ? "Changed" : "Added"} file: #{file}
#{md5}"
	oldfile_hash.delete(file)
end

oldfile_hash.each do |file, md5|
	report.puts "Deleted/Moved file: #{file}     #{md5}"
end

report.close
changed_files.close