change_created_at_property.rb

Dir.foreach('.') do |filename|
  next if filename == '.' or filename == '..'
  # Do work on the remaining files & directories
  r = /IMG_(.*?)_(.*?)[_\.].*/
  date_part = filename[r, 1]
  time_part = filename[r, 2]
  next unless date_part and time_part
  d = date_part + time_part
  d = d[0...-2]
  v = `touch -mt #{d} '#{filename}'`
  puts filename + ' => ' + d + ' => ' + v
end