From: Run Paint Run Run <redmine@...>
Date: 2009-09-05T04:51:07+09:00
Subject: [ruby-core:25376] [Bug #1755] IO#reopen Doesn't Fully Associate with Given Stream on 1.9; Ignores pos on 1.8

Issue #1755 has been updated by Run Paint Run Run.


> On your platform, ruby 1.8 seems to copy the position in the stream
> when 1.9 don't.  1.8 does simply use dup2 + fdopen, where no standard
> define if position information is shared among such file descriptors
> or not, as far as I know.  So it's up to stdio of the platform.  1.9
> implements our own I/O, so we can define the behavior.

Apologies for being dense, but does this apply only to copying across the #pos, or to all of the differences I described? IOW, is the behaviour below intentional on 1.9, i.e. by design, or operating-system dependent ("undefined")?

  $ cat reopen.rb 
  File.open('f','w') do |f|
    10000.times {|n| f.puts n }
  end
  a = File.open('f')
  b = File.open('f')
  a.reopen(b)
  a.gets
  a.reopen(b)
  p a.gets

  $ ruby -v reopen.rb 
  ruby 1.9.2dev (2009-09-03 trunk 24741) [i686-linux]
  "60\n"
  $ ruby8 -v reopen.rb 
  ruby 1.8.8dev (2009-09-04) [i686-linux]
  "0\n"

----------------------------------------
http://redmine.ruby-lang.org/issues/show/1755

----------------------------------------
http://redmine.ruby-lang.org