From: Bertram Scharpf <lists@...>
Date: 2005-05-25T04:58:09+09:00
Subject: Re: if __FILE_ == $0 executed twice

Hi,

Am Dienstag, 24. Mai 2005, 18:19:37 +0900 schrieb Han Holl:
> As recommended in the pickaxe I often have a section at the end of a
> .rb file with
> if __FILE__ == $0
> ....
> end
> 
> However, if one of the included files includes this file itself (not
> unlikely at all), the code gets executed twice.

Not here. What is your output of this:

--------------------
def gen prg, oth
  name = "#{prg}.rb"
  File.open name, "w" do |f|
    f.puts <<HERE
require "#{oth}"

puts [ __FILE__, $0].inspect

if __FILE__ == $0 then
  puts "Hello, here is `#{prg}'."
end
HERE
    name
  end
end

names = [ "a", "b"]

a, b = gen( *names), gen( *names.reverse)
system "ruby #{a}"
--------------------

Here (Debian Linux):

--------------------
["/home/user/tmp/ruby/a.rb", "a.rb"]
["/home/user/tmp/ruby/b.rb", "a.rb"]
["a.rb", "a.rb"]
Hello, here is `a'.
--------------------

Which OS are you working under?

Bertram


-- 
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de