Markdown Processor for Redcarpet version 2, for usage on the command line, in Marked etc. Supports syntax highlighting via Pygments.

github-flavored-markdown.rb

#!/usr/bin/env ruby
# Processor for Github flavored markdown, inspired by:
# https://github.com/alampros/Docter/blob/master/bin/github-flavored-markdown.rb
#
# Current version of this script can be found here:
# https://gist.github.com/1300939
#
# Adapted for Redcarpet version 2 by Ralph von der Heyden
# http://github.com/ralph
# http://twitter.com/ralph
# http://www.rvdh.de
#
# You will need the following gems:
# * redcarpet version 2
# * albino
#
# You also need the pygments library for syntax highlighting:
# sudo easy_install pygments
# Make sure the pygmentize bin is in your $PATH, or link it like that:
# sudo ln -s /usr/local/bin/pygmentize /usr/bin
#
# Make sure to chmod +x this script.
#
# Usage:
# github-flavored-markdown.rb document.md

require 'rubygems'
require 'redcarpet'
require 'albino'

class SyntaxRenderer < Redcarpet::Render::HTML
  def block_code(code, language)
    if language && !language.empty?
      Albino.colorize(code, language)
    else
      "<pre><code>#{code}</code></pre>"
    end
  end
end

def markdown(text)
  renderer = SyntaxRenderer.new(optionize [
    :with_toc_data,
    :hard_wrap,
    :xhtml
  ])
  markdown = Redcarpet::Markdown.new(renderer, optionize([
    :fenced_code_blocks,
    :no_intra_emphasis,
    :tables,
    :autolink,
    :strikethrough,
    :space_after_headers
  ]))
  markdown.render(text)
end

def optionize(options)
  options.each_with_object({}) { |option, memo| memo[option] = true }
end

puts markdown(ARGF.read)

:)

More Redcarpet-ish way to do it, removes the need to use Nokogiri entirely:

class SyntaxRenderer < Redcarpet::Render::HTML
  def block_code(code, language)
    if %w{ruby javascript}.include?(language)
      Albino.colorize(code, language)
    else
      "<pre><code>#{code}</code></pre>"
    end
  end
end

renderer = SyntaxRenderer.new(optionize [
  :with_toc_data,
  :hard_wrap,
  :gh_blockcode,
  :xhtml
])

It's nice and all, but I'd rather have the list of valid languages be generated from Albino or pygmentize or something.

Not really the point, the language part is just taken from my code, you can remove the check easily, and it'll still be more Redcartet-ish.

All right, all right, updated for great enhanced and bigger Redcartishness :)

I have ruby 1.8.7 and had to replace:

options.each_with_object({}) { |option, memo| memo[option] = true }

with

options.inject({}) { |memo, option| memo[option] = true; memo }

because each_with_object was undefined.