From: Mark Volkmann <r.mark.volkmann@...>
Date: 2006-02-28T23:23:33+09:00
Subject: Re: Q: How to initialize debugger's state when starting

On 2/23/06, Matthias Georgi <matti.georgi@gmail.com> wrote:
> A short hack.
> Make a copy of debug.rb and put these lines right after the Context
> class.
>
> class Context
>   alias original_readline readline
>   def readline(prompt, hist)
>     @rc_file ||= File.readlines("debug.rc")
>     if @rc_file.empty?
>       original_readline(prompt, hist)
>     else
>       @rc_file.shift
>     end
>   end
> end
>
> Now create a file debug.rc with your desired breakpoint:
> b 100
> b 200
>
> Start the debugger:
> ruby -r./debug myscript.rb

Cool idea!  However, if you don't have a debug.rc file, this doesn't
work. I tried to change it to handle that case as follows, but it's
still not quite right. Breakpoints I set in debug.rc are listed when I
run "b", but when I run "c" to continue execution, it doesn't stop at
them. However, if I issue the same break commands in the debugger,
they work. Can you see what I'm doing wrong?

class Context
  alias original_readline readline
  def readline(prompt, history)
    # If config file exists and hasn't been read yet, read it.
    if not @rc_file and File.exists?('debug.rc')
      @rc_file = File.readlines('debug.rc')
    end

    if @rc_file and not @rc_file.empty?
      @rc_file.shift
    else
      original_readline(prompt, history)
    end
  end
end

--
R. Mark Volkmann
Partner, Object Computing, Inc.