From: Matt Maycock <ummaycoc@...>
Date: 2004-10-10T05:05:35+09:00
Subject: Re: TempFile

Nope :-(

Here's my method that I'm using:

def handle.add
  unless block_given? then
    @done[]
    @error[ArgumentError, 'Block not given for Plot # data #
handle.add.  A block is required.']
  end

  file       = Tempfile.new('plotdata')
  filehandle, point = Object.new, @point
  filehandle.singleton_def(:puts) {|*points|
    file.puts(point[*points])
  }

  yield filehandle
  file.close(false)

  @debug[:data_file, File.readlines(file.path).map {|l| l.chomp}]
  @add[file]
end

singleton_def is just this:
  class Object
    def singleton_class
      class << self; self; end
    end
    def singleton_def(sym, &block)
      self.singleton_class.send(:define_method, sym, &block)
    end
  end

now - I at one point had
  p FileTest.exists?(file.path)
after each line after file was defined.  at one point, it was true
before the singleton_def, and false afterwards.  there are no threads
/ forking, etc.