Pandoc based markdown rendering service

Readme.md

This script spawns you a file server which serves files of various markup formats by rendering them to html. Might come handy if you are writing up something in markdown/rst/etc. and want to check the work you've done.

It needs Ruby and Pandoc (to which we refer for the list of available formatters).

wmd.rb

#!/usr/bin/env ruby

require "webrick"
require "open-uri"
require "optparse"

module WEBrick
  module HTTPServlet

    class PandocHandler < AbstractServlet
      CSSPATH = '/.css'

      def initialize(server, local_path)
        super(server, local_path)
        @local_path = local_path
        @use_css = server[:PandocCSS]
      end

      def do_GET(req, res)
        IO.popen(%w[pandoc -t html -s] + (@use_css ? ["-c", CSSPATH] : []) + [@local_path]) { |f|
          res.body = f.read
          Process.wait2(f.pid)[1].success? or raise "pandoc failed on #{@local_path}"
        }
        res['content-type'] = 'text/html; charset=utf-8'
      end
    end

  end
end

opts = { :Port => 1234, :DocumentRoot => '.',
         :DocumentRootOptions => {:HandlerTable => Hash.new(WEBrick::HTTPServlet::PandocHandler),
                                  # to work around some
                                  # issue with options
                                  :FancyIndexing => true}
       }
css = nil
OptionParser.new { |op|
  op.banner = "simple web service that renders files of various markups to html\n#{op.banner}"
  op.on('-p', '--port <port>', Integer, "listen port, default: #{opts[:Port]}") { |v| opts[:Port] = v }
  op.on('-r', '--root <dir>', "document root, default: #{opts[:DocumentRoot]}") { |v| opts[:DocumentRoot] = v }
  op.on('-c', '--css <css>') { |v|
    css = v
    opts[:PandocCSS] = true
  }
}.parse!

server = WEBrick::HTTPServer.new opts
if css
  cssdata = IO.read css

  server.mount_proc(WEBrick::HTTPServlet::PandocHandler::CSSPATH) { |req, res|
    res.body = cssdata
    res['content-type'] = 'text/css'
  }
end
%w[INT TERM].each do |signal|
  trap(signal) {server.shutdown}
end
server.start