From: Tanaka Akira <akr@...17n.org>
Date: 2005-01-26T00:27:44+09:00
Subject: Re: In need of Win32 fcntl (non-blocking)

In article <41F65F1B.80706@palli.nl>,
  Ivo Palli <ivo@palli.nl> writes:

> Instead I want to use a select, which is thankfully support in Ruby.
> However a read to a socket which has data open always seems to block,
> unless I specifically read what is available. Since I cannot know how
> much data is waiting for me, I really need to do a non-blocking read. In
> Linux it works, in Windows the fcntl call is not supported. :( As far as
> I searched and tried, there is no other way to read data without blocking.

sysread might be usable because sysread doesn't block when some data
available.  If sysread is usable, you don't need non-blocking read.

require "socket"

gs = TCPserver.open(0)
addr = gs.addr
addr.shift
printf("server is on %s\n", addr.join(":"))
socks = [gs]

loop do
  nsock = select(socks);
  next if nsock == nil
  for s in nsock[0]
    if s == gs
      ns = s.accept
      socks.push(ns)
      print(s, " is accepted\n")
    else
      begin
        print "[" + s.sysread(4096) + "]\n"
      rescue EOFError
        print(s, " is gone\n")
        s.close
        socks.delete(s)
      end
    end
  end
end
-- 
Tanaka Akira