csslint.rb

#!/usr/bin/env ruby
# OSX only
%w/ubygems grope open-uri term\/ansicolor/.each {|g| require g }

COLORS = {
  'warning' => :yellow,
  'error' => :red
}

def main
  filename_or_url = ARGV.shift

  env = Grope::Env.new
  env.load 'http://csslint.net/'

  lint = env.document.getElementById('lint')
  input = env.document.getElementById('input')

  lines = open(filename_or_url).readlines
  input.value = lines.join('')
  js = env.eval('return Grope')
  js.click(lint)

  loop do
    if env.document.querySelectorAll('table#errorView td').size > 0
      break
    end

    env.wait(1)
  end

  summary = env.document.querySelector('.resultsSummary .summary').textContent

  puts summary
  puts

  env.document.querySelectorAll('table#errorView #errors tr').each do |tr|
    nodes = tr.childNodes
    type = nodes[0].firstChild.alt
    line = nodes[1].textContent
    desc = nodes[4].firstChild.textContent

    puts Term::ANSIColor.send(COLORS[type], '%s:%s %s' % [type, line, desc])

    if line =~ /^\d+$/
      puts '> %s' % lines[line.to_i - 1]
    end
    puts
  end
end

main