#! /usr/local/bin/ruby

formats = {
  'DATE' => [/"\d{4}-\d\d-\d\d"/, '"%Y-%m-%d"'],
  'TIME' => [/"\d\d:\d\d:\d\d"/, '"%H:%M:%S"'],
  'CODE' => [/\d{8}/, '%Y%m%d'],
  'YEAR' => [/\d{4}/, '%Y'],
  'MONTH' => [/\d{1,2}/, '%m'],
  'DAY' => [/\d{1,2}/, '%d']
}

now = Time.now

File.rename "version.h", "version.h~"
open("version.h~") do |fold|
  open("version.h", "w") do |fnew|
    while line = fold.gets
      if /RUBY_RELEASE_(#{formats.keys.join('|')})/o =~ line
        regex, format = formats[$1]
        line.sub!(regex) do
          now.strftime(format).sub(/^0/, '')
        end
      end
      fnew.print line
    end
  end
end