Bug #5954: IO.read_nonblock on IO.pipe generates Errno::EBADF (MinGW)

• Status: Rejected
• Priority: Normal
• Assignee: usa (Usaku NAKAMURA)
• Target version: 3.0
• ruby -v: 1.9.3-p0 i386-mingw32 and 2.0.0dev

[luislavena (Luis Lavena)]

=begin
Originally posted in [ruby-core:42103]:

The following example seems not to work under Windows:

r, w = IO.pipe

w.write "awesome" * 10

puts r.read_nonblock(8)

r.close
w.close

C:\Users\Luis>ruby -v t.rb
ruby 1.9.3p0 (2011-10-30) [i386-mingw32]
t.rb:5:in read_nonblock': Bad file descriptor (Errno::EBADF) from t.rb:5:in '

What is not clear is that using StringIO works:

require "stringio"

b = StringIO.new

b.write "awesome" * 10
b.rewind

puts b.read_nonblock(8)

b.close

C:\Users\Luis>ruby -v t2.rb
ruby 1.9.3p0 (2011-10-30) [i386-mingw32]
awesomea

Perhaps pipes are not open properly? Is this supported under Windows?
=end

[shyouhei (Shyouhei Urabe)]

• Status changed from Open to Assigned

[usa (Usaku NAKAMURA)]

• Target version changed from 1.9.3 to 3.0

[nobu (Nobuyoshi Nakada)]

• Description updated (diff)

[luislavena (Luis Lavena)]

Hello usa, nobu.

I've hit this issue with several project again.

Can you confirm or reject if this failure is intended or a bug? That way I can decide jump into the code or not (as IO is not my strongest field)

Thank you.

[nobu (Nobuyoshi Nakada)]

It's natural.
Windows doesn't support non-blocking mode on other than sockets.

[luislavena (Luis Lavena)]

• Status changed from Assigned to Rejected

Thank you nobu, this is a platform limitation then.