Set exif dates on images based on their filename

path-to-exif.rb

require 'time'

# Files with a name like "2010-12-08 12.34.20.png" gets their
# exif dates set to that time.

files = Dir.glob('*.*g')

files.each do |file|
  date = file.to_s[0...file.to_s.length-4]
  time = Time.parse(date.gsub('.', ':'))

  formatted_date = time.strftime("%Y:%m:%d %H:%M:%S")

  cmd = "exiftool -AllDates='#{formatted_date}' -overwrite_original '#{file}'"
  system(cmd)
end