Allows to debug a cgi script in ruby with minimal effort inside an IDE.

cgitester.rb

#!/usr/bin/env ruby
$:.unshift File.join(File.dirname(__FILE__),'.','')
require 'webrick'
require 'cgi'
require 'stringio'

$cgi_input = nil

class CGI
  def stdoutput
    @str_output = StringIO.new if not defined? @str_output
    @str_output
  end
  def stdinput
    $cgi_input
  end
  def to_s
    return @str_output.string if defined? @str_output
    "EMPTY"
  end
end

class CgiTester < WEBrick::HTTPServlet::AbstractServlet

  def initialize(server)
    super
    @script_filename = "inprocess_script"
    @tempdir = server[:TempDir]
  end

  def do_GET(req, res)
    if RUBY_VERSION >= "1.9"
      load "#{ARGF.argv[0]}"
    else
      load "#{$ARGV[0]}"
    end

    cgi_in = Tempfile.new("webrick.cgi_in.", @tempdir)
    meta = req.meta_vars
    ENV.keys.each{|name| ENV.delete(name) }
    meta.each{|k, v| ENV[k] = v if v }
    if req.body and req.body.size > 0
      cgi_in.write(req.body)
    end
    cgi_in.close
    $cgi_input =  File.open(cgi_in.path)
    cgi = initCGI(CGI.new("html3"))
    $cgi_input.close
    content = cgi.to_s
    res.status = 200
    ix = content.index("\r\n\r\n")
    res.content_type = 'text/html'
    res.content_length = content.length - ix

    res.body = content[ix..-1]
  end

  alias do_POST do_GET

end


include WEBrick
s = HTTPServer.new(
    :Port => 8081
)

s.mount "/cgitester", CgiTester

trap("INT") { s.shutdown }
s.start

examplecgi.rb

require 'cgi'

def initCGI(cgi)
  cgi.out {
    cgi.head {
      cgi.title {"test title"}
    } +
    cgi.body {
      cgi.h1 {"Test Header"}
    }
  }
  return cgi
end

if __FILE__ == $0
  cgi = CGI.new("html3")
  initCGI(cgi)
end

I searched for a method to be able to easily debug cgi-scripts

• Without having to add any additional gems.
• The script can be debugged as it is intended to be deployed

Start with: ruby cgitester.rb examplecgi.rb

Open in Browser: http://localhost:8081/cgitester

Tested with ruby 1.8.7, don't use it as server, it's not thread safe

Hi, aschoerk. Tell me why this block needs? Thanks!

if FILE == $0
  cgi = CGI.new("html3")
  initCGI(cgi)
end

@JunjiUmeno, that __FILE__ == $0 check returns true when the file is being executed on it's own, and not loaded into the cgitester script. When deploying to the real webserver, Apache, or whatever webserver you are using, will invoke the script directly, instead of invoking the initCGI method like the cgitester script. Since the function as a whole is executed by the webserver the script needs to invoke initCGI on its own.