Nubish 2 - Of require and Ruby CVS

ruby-talk
1

Hi again folks,

Thanks for the excellent answers yesterday :slight_smile: I've been busy again today, and now of course I have some more questions. Only a couple, so here goes:

1) I wanted to use Rake's file commands in IRB, but was stuck because I didn't want the file ops on every object. I guess(?) this is executed by rake when it's loaded, but by experimenting a bit I found out something very interesting - if I do the following:

  def init_sh
    @sh = Object.new
    class << @sh
      require 'rake' # <= it works!!

      # rake doesn't do 'ls' with opts
      def ls(*o) `ls #{o.join(' ')}`.split("\n") end
    end
  end

then the file op methods get applied to @sh only. Now, I honestly didn't expect that to work, and I have to say it frightens me a bit. I don't know, for example, what happens with objects instantiated in that 'scope' (or is this about namespaces?) if they get passed back to the main program? I'd guess the methods are retained, because that's what happens with the sh object, right? (I can call the file ops from IRB), but I've fallen into that trap before :wink: If that's so, then what happens in case of a conflict? How does it work, and are there (m)any gotchas to watch for?

2) Also, if I change the require for include Rake (no require 'rake' anywhere), then the methods seem to get applied across all Objects, as before. I cannot understand why, esp. given 1) above.

3) I checked out Ruby CVS (HEAD) to get a look at what might be changing. I get the feeling this is an obvious question, but make says:

  [ ... ]
  gcc -g -O2 -DRUBY_EXPORT -I. -I. -c ruby.c
  gcc -g -O2 -DRUBY_EXPORT -I. -I. -c signal.c
  gcc -g -O2 -DRUBY_EXPORT -I. -I. -c sjis.c
  make: *** No rule to make target `vsnprintf.c', needed by `sprintf.o'. Stop.

I searched around a bit and found a few references, including some to moved libraries and many other programs, but not a great deal related to Ruby. Has anyone seen and maybe got past this? I'm on Fedora Core 4, Kernel 2.6.13-1.1526_FC4, gcc (GCC) 4.0.1 20050727 (Red Hat 4.0.1-5).

Thanks again in advance,

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--
Ross Bamford - rosco@roscopeco.remove.co.uk