makers-mark.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'tempfile'
require 'nokogiri'
require 'rdiscount'

# makers-mark
#
# Generates HTML from Markdown, replacing code blocks with syntax
# highlighted snippets (using the python pygments library).
#
# USAGE
#
#   $ makers-mark README.md
#
# or
#
#   $ cat README | makers-mark
class MakersMark
  def self.parse(argv)
    if idx = argv.index('-l') || argv.index('--lexer')
      lexer = argv.delete(argv[idx+1])
      argv.delete(argv[idx])
    else
      lexer = 'ruby'
    end
    
    content = argv.first ? File.read(argv.first) : $stdin.read
    content = RDiscount.new(content).to_html
    
    doc = Nokogiri::HTML(content)
    doc.search('pre code').each do |snippet|
      new(snippet, :lexer => lexer).highlight!
    end
    
    puts doc.at('body').children.to_s
  end
  
  def initialize(doc, opts)
    @doc, @opts = doc, opts
  end
  
  def highlight!
    begin  ; @doc.replace Nokogiri::HTML(run).at('div')
    ensure ; file.close! ; end
  end
  
  private
  
  def run
    `pygmentize -f html -l #{@opts[:lexer]} #{file.path}`
  end
  
  def file
    @file ||= begin
      tmp = Tempfile.new('to-highlight')
      File.open(tmp.path, 'w+') { |f| f << @doc.children.to_s }
      tmp
    end
  end
end

MakersMark.parse(ARGV.dup)