gistfile1.rb

def highlight_gists(text)
  #We set up the regexp we want to find in the string and replace it by the highlighted code
  #This regular expression detects the code used to emebed a gist and extract the id of the gist,
  #the file (for a multifile gist) and the language (the language attribute has to be added to the
  #embed code)
  regex = /<script src=\"(http|https):\/\/gist.github.com\/(\d+).js(\?file=(\S+))?\"(\s*lang=\"(.+)\")?>\s*<\/script>/
  
  text.gsub(regex) do
    if $6
      highlight_gist($2,$4,$6)
    else
      #In case no lang attribute is specified
      highlight_gist($2,$4)
    end
  end
end

def highlight_gist(gist_id, gist_file, gist_lang = "objc")
require 'open-uri'

 #This is the base address of the gist service on github
 gist_base_url = 'https://gist.github.com/'
  
  #complete gist url
  gist_url = gist_base_url + gist_id

  #url to the text version of the gist (two versions depending if we show only one file or all the gist)
  if (!gist_file.nil?) 
    gist_raw_url = gist_base_url + 'raw' + '/' + gist_id + '/' + gist_file
  else
    gist_raw_url = gist_url+'.txt'
    gist_file = "gist"
  end

  #get gist raw code from github
  gist_code = URI.parse(gist_raw_url).read
  
  #create the highlighter using albino
  syntaxer = Albino.new(gist_code, gist_lang)
  
  #output html
  html = "<div class=\"code\">"+
    "<div class=\"syntax\">"+syntaxer.colorize+"</div>"+
    "<span class=\"code_links\">"+link_to(gist_file, gist_url)+" - "+link_to("Get raw code", gist_raw_url)+"</span>"+
  "</div>"
  
  html.html_safe
end

highlighter.rb

module Highlighter
 
  def self.highlight(language, code)
    command = "pygmentize -f html -l #{language}"
    IO.popen(command, mode = 'r+') do |pygments|
      pygments << code
      pygments.close_write
      pygments.read
    end
  end
 
end