gistfile1.rb

#!/usr/local/rvm/wrappers/ruby-1.9.3-p194/ruby
require "cgi"
require "uri"
require "socket"

SCREEN_WIDTH = 1280
SCREEN_HEIGHT = 1024

cgi = CGI.new

uri = URI.parse(ENV["QUERY_STRING"])

unless uri.is_a? URI::HTTP or uri.is_a? URI::HTTPS
  puts cgi.header
  puts "<b>Invalid URI</b>"
  exit
end

if Socket.getaddrinfo(uri.host, uri.scheme).find { |_, _, hostname, ip| hostname == "localhost" or ip == "127.0.0.1" or ip == "::1" }
  puts cgi.header
  puts "<b>there is no way you are looking at localhost buddy</b>"
  exit
end

xvfb, firefox = nil

scr = 10
scr += 1 while File.exist? "/tmp/.X#{scr}-lock"

File.open "/tmp/cgi-bin-screenshot.lock", File::RDWR | File::CREAT do |f|
  begin
    f.flock File::LOCK_EX
    xvfb = Process.spawn "Xvfb", ":#{scr}", "-screen", "0", "#{SCREEN_WIDTH}x#{SCREEN_HEIGHT}x24"
    firefox = Process.spawn({ "DISPLAY" => "localhost:#{scr}.0" }, "firefox", uri.to_s, "-width", SCREEN_WIDTH.to_s, "-height", SCREEN_HEIGHT.to_s, "-no-remote")
    sleep 5 # TODO - maybe increase?
    scr_uri = "screenshots/#{uri.host}-#{rand(100000..999999)}-#{Time.now.to_s.gsub(" ", "-")}.png"
    filename = "/var/www/charlie.bz/public/#{scr_uri}"
    Process.wait Process.spawn({ "DISPLAY" => "localhost:#{scr}.0", "PATH" => "/usr/bin" }, "import", "-window", "root", filename)
    print "Location: http://charlie.bz/#{scr_uri}\r\n\r\n"
  ensure
    Process.kill 9, firefox if firefox
    Process.kill 9, xvfb if xvfb
    f.flock File::LOCK_UN
  end
end