Data Noise

Remote Debugging

I've just released a new version of ruby-debug which has a new feature: remote debugging. In order to use it you have to pass -s parameter to rdebug script:

    $ rdebug -s <script.rb>

This option makes the debugger start listening for an incoming TCP connection on port 8989, by default. You can change the default port and host name with -p and -h option respectively.

Now when the debugger is started this way, you can connect to it using this command:

    $ rdebug -c

Also since this feature is implemented using plain sockets, you can connect to the remote debugger using a plain telnet client:

    $ telnet localhost 8989
    Trying ::1...
    Connected to localhost.
    Escape character is '^]'.
    script/../config/../app/controllers/shop_controller.rb:28: product_id = params['id']
    PROMPT (rdb:3) 
    list
    [23, 32] in script/../config/../app/controllers/shop_controller.rb
       23      end
       24    end
       25  
       26    def product
       27      debugger
    => 28      product_id = params['id']
       29      unless product_id
       30        redirect_to :action => 'index'
       31        return
       32      end
    PROMPT (rdb:3) 
    cont

API Changes

One more thing. There are two important changes have been made.

• First off, starting from this version when you require 'ruby-debug', it doesn't activate the debugger by default. You have to explicitly activate it by calling Debugger#start method. Also if you want to activate remote debugging, you should start the listener server by calling Debugger#start_server(host, port) method.

  require 'ruby-debug'
  Debugger.start_server
  Debugger.start
  

• Second off, it used to be possible at the debugger prompt to type anything and the debugger evaluates the expression, now you should use eval or p command.

Win32 gem

Thanks to Max Muermann, win32 version of ruby-debug 0.1.5 is available for download. The ruby-debug 0.2 version is coming too.

Update: win32 version of ruby-debug 0.2 is now available.