Check file for changes

Check file for changes

#!/usr/bin/env ruby
# technion@lolware.net

require 'openssl'
require 'json'

# Alter the below to contain name of file to monitor
Check_File = 'testfile'

# Call a mail function here if desired
Fail_Execute = 'ls'

def gethash
  # Gets a hash of the file and turns it into JSON
  fdata = File.read(Check_File)
  digest = OpenSSL::Digest::SHA256.digest(fdata).unpack("H*").join
  thehash = { filehash: digest }
  return thehash.to_json
end

if File.exist? 'hashes.json'
  # Existing hash to check
  puts "Parsing file"
  f = File.read('hashes.json')
  j = JSON.parse(f)
  current = gethash
  testhash = JSON.parse(current)
  if j['filehash'] != testhash['filehash']
    puts "WE HAVE A DIFFERENT FILE"
    update = File.open 'hashes.json', 'w+'
    update.puts current
    update.close
    system Fail_Execute
  else
    puts "No changes to file found"
  end
else
  # Create a blank file
  d = gethash
  j = File.open 'hashes.json', 'w+'
  j.puts d
  j.close
  puts "New File Created"
end